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Integrated orchard management guide for commercial apples in the Southeast

Integrated orchard management guide for commercial apples in the Southeast

2016 Integrated Orchard Management Guide for Commercial Apples in the Southeast
Alabama Cooperative Extension System
Auburn University
University of Arkansas Division of Agriculture
Cooperative Extension Service
University of Arkansas
Clemson Cooperative Extension Service
Clemson University
University of Georgia Cooperative Extension Service
University of Georgia
North Carolina Cooperative Extension Service
North Carolina State University
University of Tennessee Agricultural Extension Service
University of Tennessee Poison Control Centers and Emergency Facilities
PESTICIDE POISONING Symptoms of pesticide poisoning may include headache, blurred vision, weakness, nausea, cramps, diarrhea, and chest discomfort. If any of these symptoms occur during or after mixing or applying pesticides or if an unintended unprotected exposure such as a spill occurs, stop work at once and take appropriate action. If pesticide is spilled on the skin, immediately wash the area thoroughly with large amounts of soap and water. If pesticide is in the eye, flush the eye for 15 minutes with running water. If pesticide is inhaled, move to open, clean air. If pesticide is ingested, rinse out the mouth. Follow all label first aid directions. Give CPR if indicated. Get help. Contact your physician or poison control center (listed below or on WPS safety poster). Transport the victim to the closest medical care facility. Take the pesticide container or the label with you, or have others search for the label and get it to the facility.
Most pesticide poisonings are due to overexposure to organophosphate and carbamate insecticides. Investigation indicates these are the result of misuse, disregard for safety precautions, and lack of proper hygiene during mixing and application. Ninety percent of occupational exposure is through the hands. Use neoprene or butyl rubber gloves. Rubber boots prevent acute exposure from spills and chronic exposure from accumulation of residues in materials of boots and shoes.
STATE-DESIGNATED POISON CENTERS
Dialing 1-800-222-1222 reaches the poison control center for the state from which the call is made.
ALABAMA
800-222-1222
Children’s of Alabama
1600 Seventh Avenue South
Birmingham, AL 35233
800-222-1222 (administration and emergency)
www.childrensal.org/rpcc
NORTH CAROLINA
800-222-1222
Carolinas Poison Center
PO Box 32861
Charlotte, NC 28232-2861
800-222-1222 (administration and emergency)
www.ncpoisoncenter.org
ARKANSAS
800-222-1222
Arkansas Poison & Drug Information Center
4301 West Markham, #522-2
Little Rock, AR 72205
501-686-6161 (administration)
www.uamshealth.com/poisoncontrol
SOUTH CAROLINA
800-222-1222
Palmetto Poison Center
University of South Carolina
Columbia, SC 29208
803-777-7909 (business)
www.poison.sc.edu
GEORGIA
800-222-1222
Georgia Poison Center Education Department
80 Jesse Hill Jr. Drive, SE
PO Box 26066
Atlanta, GA 30303
404-616-9237 (administration)
404-616-9000 (local)
404-616-9235 (education)
404-616-9287 (TDD)
www.georgiapoisoncenter.org
TENNESSEE
800-222-1222
Tennessee Poison Center
Suite 501
1313 21st Avenue South
Nashville, TN 37232
615-936-2047 (TTY)
615-936-0760 (administration) www.mc.vanderbilt.edu
(search “poison center”)
2016 Integrated Orchard Management Guide for Commercial Apples in the Southeast
Table of Contents
Pest and Orchard Management Program ....................................................... 2
Tree Row Volume: A Model for Determining Spray Volume ........................ 32
IPM Practices for Selected Pests ................................................................... 34
Pesticide Resistance Management ............................................................... 40
Effect of pH on Pesticide Activity .................................................................. 43
Orchard Floor Management.......................................................................... 44
Apple Pollination, Honey Bees, and Pesticides ............................................. 46
Soil and Plant Analysis Guidelines for Southeastern Apple Production ........ 46
Fertility Management Recommendations for Apples ................................... 48
Relative Effectiveness of Fungicides ............................................................. 49
Relative Effectiveness of Insecticides and Miticides ..................................... 53
Toxicity of Pesticides to Beneficial Arthropods ............................................. 54
Weed Response to Preemergence Herbicides .............................................. 56
Weed Response to Postemergence Herbicides ............................................ 57
Fungicides and Bactericides .......................................................................... 59
Insecticides and Miticides ............................................................................. 63
Herbicides ..................................................................................................... 68
Growth-Regulating Chemicals ....................................................................... 73
Vertebrate Management .............................................................................. 80
Pesticide Safety ............................................................................................. 86
EPA Registration Numbers of Various Materials ........................................... 87
Senior Editor: Jim Walgenbach, Extension Entomologist, N.C. State University
Section Editors:
Insect Management Jim Walgenbach
Cultural/Growth Regulators Mike Parker
Disease Management Sara Villani
Weed Management Wayne Mitchem
Vertebrate Management David Lockwood
Soils and Nutrition David Lockwood
Recommendations for the use of agricultural chemicals are included in this publication as a convenience to the reader. The use of brand names and any mention or listing of chemical products or services in this publication does not imply endorsement by the Cooperative Extension Service nor discrimination against similar products or services not mentioned. Individuals who use agricultural chemicals are responsible for ensuring that the intended use complies with current regulations and conforms to the product label. Be sure to obtain current information about usage regulations and examine a current product before applying any chemical. For assistance, contact your local Extension Agent. CONTRIBUTORS
Ed Sikora
Plant Pathology
Donn Johnson
Elena Garcia
Curt Rom
Entomology Horticulture
Horticulture
Mike Hood
Guido Schnabel Bob Bellinger
Apiculture
Plant Pathology Safety
Keith Delaplane
Dan Horton
Phillip Brannen
Harold Scherm Paul Gulliebeau
Apiculture
Entomology
Plant Pathology
Plant Pathology Safety
David Tarpy
Jim Walgenbach Wayne Mitchem
Mike Parker
Sara Villani
Apiculture
Entomology Horticulture
Horticulture
Plant Pathology
John Skinner
Frank Hale
David Lockwood Darrell Hensley
Apiculture
Entomology
Horticulture Safety
Pest and Orchard Management Program
DORMANT
Goals
Options
Relative1
Effectiveness (+)
or
Importance (*)
Amount per2
Re-entry
Interval
(hours)
Preharv.
Interval
(days)
Comments
100 gal
Acre
Cultural Management
Younger trees should be pruned closer to bud break. Prune older and bearing trees first; prune 1- to 2-year-old nonbearing trees during the month before dormant bud break.
Control canopy density, size, and shape for better light and spray penetration.
Conduct annual dormant pruning in central leader trees and appropriate high- density orchards.
*****
Provide proper nutrition for moderate tree growth and good fruit quality.
Collect soil samples; establish and maintain a good lime and fertility program. Apply late winter fertilizer to young, nonbearing trees, and half rate to mature, bearing trees.
*****
See Fertility Management section (page 48) for complete sampling, fertilizer rates, and application methods. Apply full rate to young, nonbearing trees to promote good tree growth.
Increase lateral bud break and lateral shoot development on last year’s leader growth to encourage scaffold limb development.
Bag last year’s leader growth 3 to 4 weeks before anticipated dormant bud break.
*****
See Growth-Regulating Chemicals section (page 73) for details.
Plant Growth Regulators
Control water sprout regrowth near pruning cuts and on tops of large scaffold limbs exposed to light by heavy dormant pruning.
Tre-Hold A-112
See comments.
Use 10,000 ppm (10 oz per gal) as a “sponge-on” application.
12
0
See Growth-Regulating Chemicals section (page 73) for complete recommendation details. The need for this practice depends on heaviness of pruning, size of cuts, and potential growth vigor. Effectiveness depends on COMPLETE coverage.
Control burr knot formation.
Gallex
**
Paint directly from can, full strength, on burr knots.
See Growth-Regulating Chemicals section (page 73) for recommendation details.
2 Goals
Options
Relative1
Effectiveness (+)
or
Importance (*)
Amount per2
Re-entry
Interval
(hours)
Preharv.
Interval
(days)
Comments
100 gal
Acre
Disease Management
May also help reduce inoculum of fungi that cause Brooks spot, Alternaria blotch, and Glomerella leaf spot.
Reduce inoculum of apple scab fungus.
Shred leaves with flail mower and/or apply urea to fallen leaves in autumn or spring prior to green tip.
*****
20 lb
Reduce inoculum of black, white, and bitter rot fungi.
Prune out dead wood and mummied fruit.
*****
Pruning is extremely important to reduce the likelihood of these diseases. Don’t stockpile prunings near orchard. Remove and burn, or chip with a flail mower.
Reduce inoculum of fire blight bacteria.
Prune out cankers and old fire blight strikes.
****
Will also reduce inoculum of black rot, white rot, and bitter rot.
Reduce inoculum of powdery mildew fungus.
Prune out silver-colored terminal shoots.
***
Particularly useful on young trees of a susceptible cultivar.
Improve control of cedar apple and quince rusts.
Scout orchard, adjacent woods, or borders for red cedar, and remove.
*****
Complete removal of red cedar in areas where cedars are not common may eliminate need for fungicide sprays for these diseases.
Improve conditions for drying fruit and foliage, spray penetration.
Prune to open trees.
*****
Pruning is extremely important for good disease control inside the canopy and in the tops of large trees.
Weed Management
Apply nonselective postemergence herbicide alone (mid-March). When control from this breaks and summer weeds are 2-3 inches tall, apply a nonselective postemergence herbicide with a preemergence herbicide. This will likely be in early May, but may vary from year to year. Delaying PRE herbicide application results in residual control later in the summer.
Control seedling perennials and winter annuals.
Apply glyphosate or glyphosate + 2,4-D amine or paraquat or Rely to control emerged winter annuals.
*****
+++++
See product label.
See product label.
Reduce dandelions.
2,4-D amine
++++
1 qt
1 lb
48
60
Apply at least 2 weeks before bloom to control flowering weeds. Reduces competition with apple blossoms to enhance bee pollination. Control of flowering weeds will also help control tarnished plant bug.
1Effectiveness ratings range from + = poor control to +++++ = excellent control. Importance ratings range from * = minor importance to ***** = very important.
2Rates expressed as amount per 100 gal for dilute and amount per acre are for concentrate applications based on a tree-row volume of 400 gal/acre.
3 SILVER TIP
Goals
Options
Relative1
Effectiveness (+)
or
Importance (*)
Amount per2
Re-entry
Interval
(hours)
Preharv.
Interval
(days)
Comments
100 gal
Acre
Disease Management
Control fire blight.
Bactericides
copper hydroxide
copper oxychloride sulfate Bordeaux
++++
++++
++++
See label.
See label.
See label.
See label.
See label.
See label.
This treatment will help control fire blight in blocks of trees of a susceptible cultivar where fire blight has been a problem. It will not eliminate need for streptomycin at bloom. Applications later than 0.25- to 0.5-inch green tip may result in fruit russet. Most effective if applied dilute.
Control black rot.
Fungicides
Captan 50W or
4L or
80W or
80WDG
++++
++++
++++
++++
—
—
4 lb
2 qt
2.5 lb
2.5 lb
24
24
24
24
0
0
0
0
An important spray for black rot control in Georgia. Warning: Captan will cause injury when used with or too close to oil applications.
Control crown rot
(collar rot).
Fungicides
Ridomil Gold SL
++++
See label.
48
N/A
Ridomil and Aliette applications are recommended on cultivars propagated on susceptible rootstocks planted in heavy or poorly drained soils. Apply Ridomil in the spring before growth starts, and repeat application after harvest. Apply 3 to 5 applications of Aliette a year. Make first application of Aliette after leaf emergence. Note: Ridomil and Aliette must be applied on a preventive basis. Treatment of trees exhibiting symptoms will not prevent further symptom development.
Aliette 80WDG
+++
2.5 to 5 lb
12
14
Phosphite fungicides
(i.e. Prophyt, Phostrol,
Agri-Fos)
++++
See label.
Phosphite fungicides are registered for crown rot control and have activity similar to Aliette. See labels for use instructions and precautions.
1Effectiveness ratings range from + = poor control to +++++ = excellent control. Importance ratings range from * = minor importance to ***** = very important.
2Rates expressed as amount per 100 gal for dilute and amount per acre are for concentrate applications based on a tree-row-volume of 400 gal/acre.
4 GREEN TIP TO ½-INCH GREEN
Goals
Options
Relative1
Effectiveness (+)
or
Importance (*)
Amount Per2
Re-entry
Interval
(hours)
Preharv.
Interval
(days)
Comments
100 gal
Acre
Disease Management
Control apple scab.
See discussion in Fungicides and Bactericides (page 59) for information on postinfection control program.
Fungicides
Syllit FL
+ mancozeb 75DF
or
+ Captan 80WDG
+++++
+++++
1.5 to 3 pt
3 lb
2.5 lb
48
24
24
7
77
0
Vangard 75WG
+++
5 oz
12
0
Vangard tends to be most active at cool temperatures.
Vangard 75WG
+ mancozeb 75DF
or
+ Polyram 80DF
++++
++++
3 to 5 oz
3 lb
3 lb
12
24
24
0
77
77
Scala SC
+++
7 to 10 oz
12
72
Scala SC is not compatible with Captan 50WP.
Scala SC
+ mancozeb 75DF
or
+ Polyram 80DF
++++
++++
5 oz
3 lb
3 lb
12
24
24
72
77
77
Captan 80WDG
++++
5 lb
24
0
Captec 4L
++++
0.75 to 1 qt
4 qt
24
0
Captan 50WP
++++
4 to 8 lb
24
0
Manzate ProStick
++++
3 to 6 lb
24
77, BL
Penncozeb 75DF
++++
3 to 6 lb
24
77, BL
Polyram 80DF
++++
3 to 6 lb
24
77, BL
Luna Tranquility
+ mancozeb 75DF
++++
+++++
11.2 to 16 fl oz
3 lb
12
24
72
77
1Effectiveness ratings range from + = poor control to +++++ = excellent control. Importance ratings range from * = minor importance to ***** = very important.
2Rates expressed as amount per 100 gal for dilute and amount per acre are for concentrate applications based on a tree-row-volume of 400 gal/acre.
5 GREEN TIP TO ½-INCH GREEN (continued)
Goals
Options
Relative1
Effectiveness (+)
or
Importance (*)
Amount Per2
Re-entry
Interval
(hours)
Preharv.
Interval
(days)
Comments
100 gal
Acre
Control scab (continued).
Fontelis SC
+++++
16 to 20 fl oz
12
28
Fontelis SC
+ mancozeb 75DF
+++++
+++++
16 to 20 fl oz
3 lb
12
24
28
77
Control fire blight.
Badge SC
++++
+++
3.5 to 7 pt
0.5 to 1.5 pt
48
See label.
Apply this rate between silver and green tip only.
Extended spray schedule; may harm fruit.
Badge X2
++++
+++
3.5 to 7 lb
0.5 to 1.5 lb
48
See label.
Apply this rate between silver and green tip only.
Extended spray schedule; may harm fruit.
Kocide 3000
++++
3.5 to 7 lb
48
See label.
Make application between silver and green tip; discontinue use at this rate at ½” green.
Cuprofix Ultra Disperss 40DF
++++
5 to 7.5 lb
48
See label.
Apply this rate between silver and green tip only.
Champ Formula 2F
++++
5.3 to 10.5 pt
48
See label.
Apply this rate between silver and green tip only.
Control Phytophthora rots.
Phostrol
+++++
0.6 pt
2 to 5 pt
4
0
Prophyt
+++++
2 to 4 pt
4
0
1Effectiveness ratings range from + = poor control to +++++ = excellent control. Importance ratings range from * = minor importance to ***** = very important.
2Rates expressed as amount per 100 gal for dilute and amount per acre are for concentrate applications based on a tree-row-volume of 400 gal/acre.
6 GREEN TIP TO ½-INCH GREEN (continued)
Goals
Options
Relative1 Effectiveness (+)
or
Importance (*)
Amount Per2
Re-entry Interval (hours)
Preharv. Interval (days)
Comments
100 gal
Acre
Insect Management
Use either a superior-type or highly refined summer oil applied dilute. If the oil application is delayed until tight cluster to pink, use a refined oil or reduce a superior type to ½ to 1 gal/100 gal. Do not use captan within 2 weeks of an oil application.
Control scales and reduce overwintering European red mite and rosy apple aphid eggs.
Insecticides
Oil
+++++
2 gal
2 to 3% solution
12
0
Improve scale control.
Oil +
Lorsban 4E
or
Esteem 35WP
or
Centaur 70WDG
++++
+++++
+++++
2 gal
½ to 1 pt
—
—
8 gal
2 to 4 pt
4 to 5 oz
9 to 12 oz
12
96
12
12
0
DD
45
14
An insecticide with oil may be added at this time in orchards experiencing problems with scales. This option is recommended in orchards that experienced scale problems the previous year. The window of control with Esteem or Centaur can be extended to first cover. NOTE: if using Esteem or Centaur, application can be made anytime between green tip and 1st Cover.
Initiate oriental fruit moth (OFM) monitoring program.
Erect pheromone traps.
*****
Erect pheromone traps by green tip to detect first emergence. See section on IPM Practices for Selected Pests (page 34) for monitoring information.
Mating disruption for OFM and codling moth.
Pheromones
Isomate CM/OFM TT
CheckMate Puffer - CM/OFM
+++++
++++
(number of dispensers)
200/acre
1/acre
Now is the time to begin erecting pheromone dispensers for mating disruption. Combination dispensers that contain both OFM and codling moth pheromone are recommended. Hanging of dispensers in trees should be complete by the end of bloom. See section on “Mating Disruption” in IPM Practices for Selected Pests (page 37).
1Effectiveness ratings range from + = poor control to +++++ = excellent control. Importance ratings range from * = minor importance to ***** = very important.
2Rates expressed as amount per 100 gal for dilute and amount per acre are for concentrate applications based on a tree-row-volume of 400 gal/acre.
7
7 TIGHT CLUSTER TO PINK
Goals
Options
Relative1
Effectiveness (+)
or
Importance (*)
Amount per2
Re-entry
Interval
(hours)
Preharv.
Interval
(days)
Comments
100 gal
Acre
Disease Management
Control apple scab.
Fungicides
Captan 80WDG
Captan 50WP
Captec 4L
Manzate ProStick
Penncozeb 75DF
Polyram 80DF
Flint WG
Sovran WG
Indar 2F
Luna Tranquility
Luna Sensation
Merivon
Fontelis
Inspire Super
Aprovia
++++
++++
++++
++++
++++
++++
+++++
+++++
+++++
++++
+++++
+++++
+++++
+++++
+++++
0.75 to 1 qt
5 lb
4 to 8 lb
4 qt
3 to 6 lb
3 to 6 lb
3 to 6 lb
2 to 2.5 oz
3.2 to 6.4 oz
6 to 8 fl oz
11.2 to 16 fl oz
4 to 5.8 fl oz
4 to 5.5 fl oz
16 to 20 fl oz
12 fl oz
5.5 to 7 fl oz
24
24
24
24
24
24
12
12
12
12
12
12
12
12
12
0
0
0
77, BL
77, BL
77, BL
14
30
14
72
14
0
28
14
30
Combine Flint WG with a half rate of mancozeb or captan for resistance management.
For resistance management combine Fontelis with half rate of mancozeb. See label for Fontelis rates when applied with mancozeb.
Control powdery mildew.
Fungicides
Rally 40WSP
Procure 50WS
Indar 2F
Topguard 1.04SC
Luna Sensation 500SC
Luna Tranquility 4.16SC
Merivon 4.18SC
Fontelis 1.67SC
Flint 50WG
Sovran 50WDG
Aprovia
JMS Stylet Oil
Microthiol Disperss
+++++
++++
++++
+++++
+++++
++++
+++++
+++
++++
+++++
++++
+++
++++
1 to 2 gal
5 to 10 oz
4 to 8 oz
8 fl oz
8 to 12 fl oz
4 to 5.8 fl oz
11.2 to 16 fl oz
4 to 5.5 fl oz
14 to 20 fl oz
2 to 2.5 oz
4 to 6.4
5.5 to 7 fl oz
10 to 20 lb
24
12
12
12
12
12
12
24
12
12
12
4
24
14
14
14
14
14
72
0
28
14
30
30
0
See label.
Tight cluster to petal fall are the most important sprays for the control of powdery mildew.
Do not use EC or solvent-based products, crop oil concentrate, or methylated seed oil adjuvants with Merivon.
Applying Stylet Oil with or following an application of captan will cause severe phytotoxicity.
1Effectiveness ratings range from + = poor control to +++++ = excellent control. Importance ratings range from * = minor importance to ***** = very important.
2Rates expressed as amount per 100 gal for dilute and amount per acre are for concentrate applications based on a tree-row volume of 400 gal/acre.
8 TIGHT CLUSTER TO PINK (continued)
Goals
Options
Relative1
Effectiveness (+)
or
Importance (*)
Amount per2
Re-entry
Interval
(hours)
Preharv
Interval
(days)
Comments
100 gal
Acre
Control cedar apple rust and quince rust.
Fungicides
Use a DMI (FRAC 3) fungicide used for powdery mildew or apple scab, or:
mancozeb 75DF
++++
3 lb
24
77
DMI fungicides have after-infection activity on rusts.
Mancozeb and Polyram do not control powdery mildew.
Control black rot and frogeye leafspot.
Captan 50WP
Captan 4L
Captan 80WDG
Thiophanate Methyl 85WDG
Topsin 4.5FL
Topsin M WSB
++++
++++
++++
+++++
+++++
+++++
0.5 to 1 qt
0.2 to 0.3 lb
3.8 to 5 fl oz
0.2 to ¼ lb
4 to 8 lb
3 to 4 qt 2.5 to 5 lb
0.6 to 0.8 lb
15 to 20 fl oz
¾ to 1 lb
24
24
24
48
48
48
0
0
0
1
1
1
Captan does not control powdery mildew or rust diseases.
Many populations of apple scab are resistant to T-Methyl and Topsin fungicides.
Insect Management
Erect traps now because moths begin to emerge near bloom. See section on IPM Practices for Selected Pests (page 34) for information on monitoring programs.
Initiate codling moth and leafroller monitoring program.
Erect pheromone traps.
*****
Control rosy apple aphid.
Insecticides
Actara 25WDG
Assail 30SG
Calypso 4F
Belay SC
Sivanto 200SL
Asana XL
Danitol 2.4EC
Permethrin 3.2EC
+++++
+++++
+++++
+++++
++++
++++
++++
++++
—
—
—
—
—
2 to 5.8 fl oz
2.6 to 4.3 oz
—
4.5 oz
2.5 to 4 oz
2 to 4 oz
6 fl oz
7 to 10 oz
4.8-14.5 fl oz
10.6-21.3 oz
4 to 10 fl oz
12
12
12
12
4
12
24
12
35
7
30
21
14
7
14
*
Pink stage is the best time to control rosy apple aphid. Caution: Rosy apple aphid resistance to pyrethroids has been observed in some orchards. See Rosy Apple Aphid resistance section (page 41). Pyrethroids can lead to flare-ups of mites, scales, and woolly apple aphids.
*Do not apply Permethrin after petal fall.
1Effectiveness ratings range from + = poor control to +++++ = excellent control. Importance ratings range from * = minor importance to ***** = very important.
2Rates expressed as amount per 100 gal for dilute and amount per acre are for concentrate applications based on a tree-row volume of 400 gal/acre.
9 TIGHT CLUSTER TO PINK (continued)
Goals
Options
Relative1
Effectiveness (+)
or
Importance (*)
Amount per2
Re-entry
Interval
(hours)
Preharv
Interval
(days)
Comments
100 gal
Acre
Control plant bugs
and spotted tentiform leafminer (STLM).
Maintain clean ground-cover. Insecticides listed for rosy apple aphid will aid in plant bug and leafminer control if plant bugs are readily seen.
*****
In many instances, a clean groundcover eliminates the need for insecticides to control bugs. If there is a history of plant bug problems, a second application at petal fall will improve control. Insecticides specifically targeting STLM are rarely needed because biological control agents are highly effective.
1Effectiveness ratings range from + = poor control to +++++ = excellent control. Importance ratings range from * = minor importance to ***** = very important.
2Rates expressed as amount per 100 gal for dilute and amount per acre are for concentrate applications based on a tree-row volume of 400 gal/acre.
10 BLOOM
Goals
Options
Relative1
Effectiveness (+)
or
Importance (*)
Amount per2
Re-entry
Interval
(hours)
Preharv.
Interval
(days)
Comments
100 gal
Acre
Cultural Management
Loosen bags on leaders to acclimate for 2 to 3 days; then remove bags from leaders and spray with Promalin or Perlan.
Leader bags must be removed when new lateral growth is 1 to 3 inches long.
*****
See Growth-Regulating Chemicals section (page 73) for complete details.
Do leader selection and strip whorl on dormant headed tree leaders.
Select new shoot for central leader and remove competing shoots from first four nodes below new leader shoot.
Plant Growth Regulators
See Growth-Regulating Chemicals section (page 73). Apply as a fine mist application at 40 to 50% of Tree Row Volume (TRV) water rate between early king bloom and early petal fall of the side blossoms. Split applications during this period can be more effective.
Improve fruit shape and increase fruit weight of Red and Golden Delicious and Gala.
(BA+GA 4 + 7)
Promalin
Perlan
+++
+++
0.5 to 1 pt
1 to 2 pt
4
4
None
Increase lateral bud break and lateral shoot growth on 1-year-old leader growth as a tool to encourage scaffold limb development, especially on those that were bagged before bud break. Use on nonbearing trees only.
Promalin
Perlan
+++++
+++++
125 to 500 ppm
(0.5 to 2 pt)/
10 gal
125 to 500 ppm
(0.5 to 2 pt)/
10 gal
4
4
None
Apply to last year’s leader growth at 1-3 inches of new terminal growth with a handheld nozzle. See Growth-Regulating Chemicals section (page 73).
Make one application when orchard trees have 1 to 3 inches of new growth or when the leader has reached the height where branching is required.
1Effectiveness ratings range from + = poor control to +++++ = excellent control. Importance ratings range from * = minor importance to ***** = very important.
2Rates expressed as amount per 100 gal for dilute and amount per acre are for concentrate applications based on a tree-row-volume of 400 gal/acre.
11 BLOOM (continued)
Goals
Options
Relative1
Effectiveness (+)
or
Importance (*)
Amount per2
Re-entry
Interval
(hours)
Preharv.
Interval
(days)
Comments
100 gal
Acre
To increase fruit set after a frost.
Promalin
Perlan
++
++
16-32 fl. oz
16-32 fl. oz
Apply within 24 hours after a frost that occurs when most of the crop is between early bloom and full bloom. Apply in 75 to 150 gallons of water per acre. Do not apply to frozen foliage, blossoms, or developing fruit. Allow trees to completely thaw prior to application. Do not use a surfactant.
Disease Management
Control apple scab, rusts, powdery mildew, and black rot.
Fungicides
Same fungicides as for tight cluster.
Avoid sprays in full bloom if possible. Do not overextend application intervals.
Control fire blight.
Bactericides
Streptomycin
(i.e. Agri-mycin, Firewall, Streptrol)
Kasumin 2L
Mycoshield 17WP
Fireline
Actigard
+ streptomycin
or
+ oxytetracyline
Bloomtime Biological
Cueva
Double Nickel LC
+ Cueva
Serenade Optimum
MasterCop
Badge SC
Badge X2
+++++
+++++
++++
++++
+++++
++++
++
+++
+++
++
+++
+++
+++
64 fl oz
1 lb
12 oz
0.125 to 0.8 oz
0.75 to 1 lb
24 oz
-
-
-
0.5 to 3.2 oz
24 oz
0.33 lb
2 to 3 qt
1 to 2 qt
2 to 3 qt
14 to 20 oz
0.5 to 1.5 qt
0.5 to 1.5 pt
0.5 to 1.5 lb
12
12
12
12
12
4
4
4
4
48
48
48
50
90
60
60
60
See label.
0
0
0
See label.
See label.
See label.
Begin application at first bloom and continue at 3- to 4-day intervals until petal fall. It is very important to continue spraying through late “rat-tail” bloom, especially on susceptible varieties. See discussion under Pesticide Resistance Management section (page 40) for timing sprays according to conditions favorable for infection.
Bloomtime Biological is not compatible with coppers. Approved for organic production.
Cueva may result in phytotoxicity to fruit and leaves. If concerned, use lower rate. OMRI approved.
Serenade Optimum is approved for organic production.
Badge X2 is OMRI approved.
Insect Management
Keep orchard floor free of flowering weeds. This will increase pollination in the trees and lessen bee activity after apple bloom.
Protect pollinators.
12 PETAL FALL
Goals
Options
Relative1
Effectiveness (+)
or
Importance (*)
Amount per2
Re-entry
Interval
(hours)
Preharv.
Interval
(days)
Comments
100 gal
Acre
Cultural Management
If boron is low in leaf sample or cork spot has been a problem in past years, a second and third application may be used. Dilute applications are necessary for good uptake. See Fertility Management section (page 48).
Reduce fruit corking.
Solubor
or
Borosol
+++
+++
1 lb
at first cover
1 pt
Reduce fruit corking and bitter pit.
calcium chloride
+++
2 lb
beginning at first cover
Repeat calcium sprays in each cover spray all season. Do not apply calcium chloride when temperatures are above 85°F, and DO NOT tank mix with Solubor or Apogee. All calcium sprays should be applied dilute for maximum response, especially for bitter pit control in late season cover sprays when fruit are becoming waxy. See Fertility Management section (page 48).
Plant Growth Regulators
Reduce fruit russeting on susceptible cultivars (esp. Golden Delicious).
(GA4+7)
ProVide 10SG
Novagib 10L
++++
++++
2.1 to 3.5 oz
(60 to 100 g)
20 to 33 fl. oz
4
4
None
At petal fall, begin the first of 2 to 4 applications at 7- to 10-day intervals. See Growth-Regulating Chemicals section (page 73) for complete recommendations.
Thin fruit to reduce crop load and encourage return bloom.
Depends on cultivar, fruit size, and thinning chemical. Applications from petal fall to about 8 mm would be applied during this time.
+++++
See thinning chart on page 76.
Check label for specific thinning chemical(s) to be used.
See Chemical Fruit Thinning Spray and Apple Thinning recommendations chart in Growth-Regulating Chemicals section.
Initiate vegetative growth control applications.
Suppress shoot blight.
Prohexadione Calcium
(Apogee or Kudos)
++++
Use at TRV calculated a.i./acre.
9 to 24 fl. oz
12
45
See prohexadione calcium table in Growth-Regulating Chemicals section (page 78).
1Effectiveness ratings range from + = poor control to +++++ = excellent control. Importance ratings range from * = minor importance to ***** = very important.
2Rates expressed as amount per 100 gal for dilute and amount per acre are for concentrate applications based on a tree-row-volume of 400 gal/acre.
13 PETAL FALL (continued)
Goals
Options
Relative1
Effectiveness (+)
or
Importance (*)
Amount per2
Re-entry
Interval
(hours)
Preharv.
Interval
(days)
Comments
100 gal
Acre
Disease Management
Control apple scab.
Fungicides
Same fungicides as recommended for tight cluster/pink and bloom stages.
Plant tissue during early shoot growth can be very sensitive to injury by captan. Be careful with tank mixtures containing captan and adjuvants.
Control black rot and white rot.
Fungicides
Captan 50 WP
Captec 4L
Captan 80WDG
Sovran 50WG
Flint 50WG
Thiophanate Methyl 85WDG
Topsin 4.5FL
Topsin M WSB
++++
++++
++++
++++
+++++
+++++
+++++
+++++
1 qt
0.2 to 0.3 lb
3.75 to 5 fl oz
0.2 to 0.25 lb
8 lb
4 qt
5 lb
4 to 6.4 oz
1.5 to 2.5 oz
0.6 to 0.8 lb
15 to 20 fl oz
¾ to 1 lb
24
24
24
12
12
48
48
48
0
0
0
30
14
1
1
1
Control Colletotrichum pathogens: Glomerella leaf spot/Bitter rot.
Fungicides
Captan 50 WP
Captec 4L
Captan 80WDG
Ziram 76 DF
++++
++++
++++
++++
1 qt
8 lb
4 qt
5 lb
6 lb
24
24
24
48
0
0
0
14
Mancozeb is not specifically labeled for Colletotrichum pathogens in apple. If applying mancozeb for control of apple scab, use a half rate of captan and a half rate of mancozeb.
ProPhyt
+ Captan 80 WDG
or
+ Ziram 76 DF
+++++
1.5 lb
4 pt
3.75 lb
6 lb
4
24
48
0
0
14
ProPhyt can also be applied in tank mixture with mancozeb (3 lb rate) if mancozeb is applied for protection against apple scab and cedar apple rust.
Sovran 50WG
++++
4 to 6.4 oz
12
30
Sovran and Flint will also control apple scab and powdery mildew.
Flint 50WG
+++++
2.5 to 3 oz
12
14
Pristine 38W
+++++
14.5 to 18 oz
12
0
Merivon 4.18SC
+++++
4 to 5.5 fl oz
12
0
Omega 500F
++++
13.8 fl oz
12
28
14 Goals
Options
Relative1
Effectiveness (+)
or
Importance (*)
Amount per2
Re-entry
Interval
(hours)
Preharv.
Interval
(days)
Comments
100 gal
Acre
Control Brooks fruit spot.
Fungicides
Use protectant fungicides (captan, mancozeb, Ziram) or benzimidazole fungicides (i.e. benzimidazoles) listed above for summer rots.
*****
Petal fall through third cover sprays are the most important sprays for Brooks spot control. Generally, the EBI and QoI fungicides may have limited Brooks spot activity. If one of them is used, combine it with a full rate of protectant.
Control powdery mildew and cedar apple rust.
Fungicides
See tight cluster to pink spray.
If captan alone is used in this application, fungicides with strong activity on powdery mildew and cedar apple rust should be included in this application.
Insect Management
*When choosing an insecticide at petal fall or any other time, choose one that provides control of the spectrum of insects present at the time of application.
Preventive control of mites is not recommended unless insecticides known to flare mites are anticipated to be used.
An application of Agri-Mek at petal fall to first cover should provide season-long suppression of these pests. A paraffinic spray oil (0.25% or 1 gal/acre) must be tank mixed to ensure Agri-Mek’s activity. Do not use captan 2 weeks before or after applying oil with Agri-Mek.
Preventively control European red mite, spotted tentiform leafminer, and white apple leafhopper.
Insecticides
Agri-Mek 0.15EC
+
oil
+++++
2.5 oz
10 oz
12
28
Preventive control of European red mite.
Apollo SC
Savey 50WP
Zeal 72WDG
Envidor 2SC
++++
++++
+++++
+++++
—
—
—
—
4 oz
3 oz
2 to 3 oz
16 to 18 oz
12
12
12
12
45
28
28
7
Apply one of these products between petal fall and third cover or when mites reach one adult per leaf. See page 41 for resistance management of European red mite.
1Effectiveness ratings range from + = poor control to +++++ = excellent control. Importance ratings range from * = minor importance to ***** = very important.
2Rates expressed as amount per 100 gal for dilute and amount per acre are for concentrate applications based on a tree-row-volume of 400 gal/acre.
15 PETAL FALL (continued)
Goals
Options
Relative1
Effectiveness (+)
or
Importance (*)
Amount per2
Re-entry
Interval
(hours)
Preharv.
Interval
(days)
Comments
100 gal
Acre
Control plum curculio.
Insecticides
Avaunt 30WG
Actara 25SDG
Imidan 70WP
Belay SC
Sevin 50WP
+++++
+++++
++++
++++
+++
—
—
¾ lb
—
½ lb
5 to 6 oz
4.5 oz
3 lb
6 oz
1 lb
12
12
24
12
12
28
35
7
7
3
Adults begin to enter orchards during bloom, with most, but not all, adults present by late petal fall. An insecticide applied at petal fall is important to minimize damage. Cool weather during this period, or historically large populations, may extend adult activity, which may require a second application 10 days later.
Control oriental fruit moth.
Insecticides
Imidan 70WP
Avaunt 30WG
Sevin 50WP
Assail 30SG
Mating Disruption
Isomate OFM-TT
CheckMate OFM-F
+++++
+++++
+++
+++++
+++++
+++++
¾ lb
—
½ lb
—
3 lb
5 to 6 oz
2 lb
5 to 8 oz
50-100 disp.
1 to 2 fl oz
24
12
12
12
0
0
7
28
3
7
0
0
An insecticide applied between 500 and 600 degree days (DD) after biofix will control the first generation. First generation OFM is controlled with a single application of an insecticide at petal fall.
In those orchards not using mating disruption (e.g., Isomate TT or Puffers), CheckMate OFM-F, a sprayable formulation, should be considered in early to mid August for control of late-season OFM. A second application in early September may be necessary for later-maturing varieties.
Control San Jose scale.
Insecticides
Diazinon 50WP
Esteem 0.86EC
Centaur 70WP
Movento 2SC
Assail 30SG
summer oil
+++++
+++++
+++++
+++++
+++
+++
1 lb
—
—
—
—
—
4 lb
4 oz
34.5 oz
6 to 9 oz
8 oz
1 to 2%
96
12
12
24
12
12
21
45
14
7
7
0
Where scales have been a problem the previous year, apply an insecticide for first generation crawlers, which are active from petal fall through third cover. Yellow crawlers can be detected by wrapping double-stick tape around infested limbs after bloom and inspecting weekly. Caution: Diazinon or oil applied with captan or Captec may cause phytotoxicity.
Control rosy apple aphid.
Insecticides
Admire 4.6SC
Actara 25WP
Assail 30SG
Sivanto 200SL
Movento 2SC
+++++
+++++
+++++
+++++
++++
—
—
—
—
—
2.8 oz
4.5 oz
2.5 to 4.0 oz
7 to 10 oz
6 to 9 oz
12
12
12
4
24
7
35
7
14
7
If an insecticide was not applied for rosy apple aphid at pink, or if control was poor, an insecticide should be applied. An adjuvant must be applied with Movento.
See Rosy Apple Aphid resistance section (page 41).
16 Goals
Options
Relative1
Effectiveness (+)
or
Importance (*)
Amount per2
Re-entry
Interval
(hours)
Preharv.
Interval
(days)
Comments
100 gal
Acre
Control white apple leafhopper.
Insecticides
Sevin 50WP
Actara 25WDG
Admire 4.6SC
Assail 30SG
Avaunt 30WG
Sivanto 200SL
+++++
+++++
+++++
+++++
+++++
+++++
½ lb
—
—
—
—
—
2 lb
2 to 2¾ oz
2.8 oz
2.5 to 4 oz
5 to 6 oz
7 to 10 oz
12
12
12
12
12
4
1
35
7
7
28
14
Threshold level for first generation white apple leafhopper is 1 nymph per leaf. Thinning apples with Sevin during this time controls leafhoppers. Leafhoppers may be present from petal fall to second cover spray.
Control spotted tentiform leafminer.
Insecticides
Actara 25WDG
Delegate WG
Provado 1.6F
Assail 30SG
++++
+++++
++++
++++
—
—
1 to 2 oz
—
4.5 oz
4.5 oz
4 to 8 oz
1.1 oz
12
4
12
12
35
7
7
7
Threshold level for first generation leafminer is one mine per leaf. The need for leafminer control is rare, as biological control is highly effective.
Control green fruitworm.
Insecticides
Intrepid 2F
+++++
—
6 to 8 fl oz
4
14
Scout trees for feeding damage on shoots and new apples. An application of Intrepid at early petal fall will help to minimize damage to fruit. Intrepid is highly safe to bees and can be sprayed during bloom.
Weed Management
Control weeds.
Check orchards for weed populations.
*****
Identify weed problems so herbicide program can be adjusted for summer weed control.
Apply PRE + Nonselective POST herbicide.
See herbicide guide.
*****
See product labels.
See product labels.
Apply when summer weeds are 2 to 3 inches tall. Delaying application of preemergence herbicides until early May extends summer weed control.
Suppress clover bloom to protect bees from insecticide sprays.
2,4-D
*****
1 qt
48
60
Apply 2,4-D 7 to 10 days before spraying insecticides to suppress clover and avoid killing bees.
1Effectiveness ratings range from + = poor control to +++++ = excellent control. Importance ratings range from * = minor importance to ***** = very important.
2Rates expressed as amount per 100 gal for dilute and amount per acre are for concentrate applications based on a tree-row-volume of 400 gal/acre.
17 FIRST COVER
Goals
Options
Relative1
Effectiveness (+)
or
Importance (*)
Amount per2
Re-entry
Interval
(hours)
Preharv.
Interval
(days)
Comments
100 gal
Acre
Disease Management
If primary apple scab is controlled early, continue to protect with captan. Products used for summer disease control, with the exception of benzimidazoles (due to resistance concerns) should also generally be effective against apple scab. DMI fungicides will provide post-infection activity as well.
Control apple scab.
Fungicides
Scout for secondary apple scab. See comments.
*****
Control blister spot.
Fungicides
Aliette WDG
Phostrol
++++
++++
0.5 to 1 gal
2.5 to 5 pt
12
4
14
0
Fruit are most susceptible to blister spot 2 to 8 weeks following petal fall.
Control flyspeck/sooty blotch.
Fungicides
Captan 50WP
Captec 4L
Captan 80WDG
Sovran 50WG
Flint 50WG
Thiophanate Methyl 85WDG
Topsin 4.5FL
Topsin M WSB
Ziram 76 DF
Inspire Super
Indar 2F
Aprovia
Luna Sensation
Merivon
Pristine 38WDG
Cueva
Double Nickel LC
+ Cueva
++++
++++
++++
++++
+++++
+++++
+++++
+++++
++++
+++++
++++
+++++
+++++
+++++
+++++
+++
+++
0.5 to 1 qt
1 to 1.6 oz
0.15 to 0.2 lb
3.75 to 5 fl oz
0.2 to 0.25 lb
4 to 8 lb
2 to 4 qt
2.5 to 5 lb
4 to 6.4 oz
1.5 to 2.5 oz
0.6 to 0.8 lb
15 to 20 fl oz
¾ to 1 lb
6 lb
12 fl oz
6 to 8 fl oz
5.5 to 7 fl oz
4 to 5.8 fl oz
4 to 5.5 fl oz
14.5 to 18.5 oz
2 to 3 qt
1 to 2 qt
2 to 3 qt
24
24
24
12
12
48
48
48
48
12
12
12
12
12
12
4
4
0
0
0
30
14
1
1
1
12
14
14
30
14
0
0
0
0
For resistance management, it is recommended that single site fungicides be applied in tank mixture with a protectant fungicide such as captan.
Cueva may result in phytotoxicity to some apple cultivars.
1Effectiveness ratings range from + = poor control to +++++ = excellent control. Importance ratings range from * = minor importance to ***** = very important.
2Rates expressed as amount per 100 gal for dilute and amount per acre are for concentrate applications based on a tree-row-volume of 400 gal/acre.
18 Goals
Options
Relative1
Effectiveness (+)
or
Importance (*)
Amount per2
Re-entry
Interval
(hours)
Preharv.
Interval
(days)
Comments
100 gal
Acre
Control fire blight.
Apogee
Firewall 17WP
or other strepto-mycin products
Cueva
or other low MCE product
+++++
+++++
+++
4.5 to 9 fl oz
24 oz
2 qt
12
12
4
45
50
0
Apply Apogee when shoots are 1 to 3 inches long and 14 to 21 days after initial application.
Application of streptomycin regularly during summer cover applications is believed to hasten development of resistance.
Cueva may cause phytotoxicity, particularly on sensitive cultivars.
Control Alternaria leaf blotch, black rot, white rot.
Refer to fungicides used for Petal Fall application.
Control Colletotrichum pathogens: Glomerella leaf spot/Bitter rot.
Refer to fungicides used for Petal Fall application.
Control powdery mildew.
Refer to fungicides used for Petal Fall application.
1Effectiveness ratings range from + = poor control to +++++ = excellent control. Importance ratings range from * = minor importance to ***** = very important.
2Rates expressed as amount per 100 gal for dilute and amount per acre are for concentrate applications based on a tree-row-volume of 400 gal/acre.
19 FIRST COVER (continued)
Goals
Options
Relative1
Effectiveness (+)
or
Importance (*)
Amount per2
Re-entry
Interval
(hours)
Preharv.
Interval
(days)
Comments
100 gal
Acre
Insect Management
Control codling moth.
Monitor codling moth adult activity.
Insecticides
Delegate 25WP
Altacor 35WDG
Exirel 0.83SE
Voliam Flexi
Belt 4SC
Intrepid 2F
Rimon 0.83EC
Imidan 50WP
Assail 30SG
CYD-X
*****
+++++
+++++
+++++
+++++
++++
++++
++++
++++
+++
++++
—
—
—
—
—
—
—
¾ lb
—
—
4.5 to 7 oz
2.5 to 4.5 oz
8.5 to 17 oz
4 to 7 oz
3 to 5 fl oz
10 to 16 oz
20 to 40 oz
3 lb
4 to 8 oz
1 to 3 oz
4
4
12
12
12
4
12
24
12
4
7
5
3
35
14
14
14
7
7
0
See IPM Practices for codling moth (page 34) to determine how to minimize insecticide applications for codling moth control.
Voliam Flexi (which is a mixture) is recommended only at first cover when late emerging plum curculio is a concern, and a minimum of 6.0 oz should be used.
CYD-X is a virus that controls only codling moth. Frequent applications (7 to 10 days) at low rates (1 to 2 oz per acre) have worked well in field trials.
Codling moth insecticide-resistant populations exist in some orchards and can affect the performance of certain products.
Control rosy apple aphid, plum curculio, white apple leafhopper, spotted tentiform leafminer, and San Jose scale.
Monitor orchards for these insects.
Insecticides
(See Petal Fall section,
page 13)
*****
Infestations of these insects may occur anytime from petal fall to the second cover spray. Early detection is important for effective control.
1Effectiveness ratings range from + = poor control to +++++ = excellent control. Importance ratings range from * = minor importance to ***** = very important.
2Rates expressed as amount per 100 gal for dilute and amount per acre are for concentrate applications based on a tree-row-volume of 400 gal/acre.
19
20 SECOND COVER AND LATER SPRAYS
Goals
Options
Relative1
Effectiveness (+)
or
Importance (*)
Amount per2
Re-entry
Interval
(hours)
Preharv.
Interval
(days)
Comments
100 gal
Acre
Cultural Management
See information listed in Petal Fall to First Cover sections (pages 13 through 17) and Fertility Management section (page 48).
Reduce fruit corking and bitter pit.
calcium nitrate
calcium chloride
+++
+++
3 lb
2 lb
Provide proper nutrition for moderate tree growth and good fruit quality.
Apply second half of fertilizer to mature, bearing trees if crop load is present, as soon as frost/freeze danger is past (approximately second cover).
++++
See Fertility Management Recommendations section (page 48) for fertilizer use suggestions and complete recommendations.
Collect leaf samples in July to mid-August for leaf analysis.
+++++
See Fertility Management Recommendations section (page 48) for complete details.
Achieve proper tree training, and control tree size and density for good light and spray penetration.
Select lateral limbs, strip whorls, establish wide crotch angles with toothpicks or clothespins, and prop limbs to good limb angles (60-90° for central leader trees and 75-85° below vertical for high density, slender, spindle-type trees).
++++
Tree training is mandatory to develop proper lateral branching and limb position.
Do detailed young tree management (deshoot, position limbs, tie up leader) every 6 to 8 weeks until full tree size and bearing are achieved (especially for high density orchards).
++++
Summer pruning is a necessary extension of tree training begun earlier. Summer pruning helps contain tree size and density, and proper limb selection and positioning encourage flower initiation.
Remove water sprouts.
++++
Removing upright water sprout growth reduces canopy density, allowing greater spray penetration and better light distribution for fruit quality and color development. Summer pruning and removal of water sprouts also help control sooty blotch and flyspeck.
Do leader manipulation, such as summer bending or snaking, every 18 inches of terminal growth extension.
++
1Effectiveness ratings range from + = poor control to +++++ = excellent control. Importance ratings range from * = minor importance to ***** = very important.
2Rates expressed as amount per 100 gal for dilute and amount per acre are for concentrate applications based on a tree-row volume of 400 gal/acre.
21 SECOND COVER AND LATER SPRAYS (continued)
Goals
Options
Relative1
Effectiveness(+)
or
Importance (*)
Amount per2
Re-entry
Interval
(hours)
Preharv.
Interval
(days)
Comments
100 gal
Acre
Plant Growth Regulators
Thin to reduce crop load and encourage return bloom.
Depends on cultivar, fruit size, and thinning chemical selected. Application time from approximately 9 mm and larger would be applied from second cover on.
+++++
See thinning chart on page 76.
See Chemical Fruit Thinning Sprays (page 73) and Apple Thinning Recommendations chart (page 76) in Growth-Regulating Chemicals section.
Enhance return bloom.
Fruitone L or PoMaxa
Ethrel
+++
+++
2-8 fl. oz
16 to 72
fl. oz
48
48
2
7
Studies in the Southeast have found that NAA or Ethrel treatments can improve return bloom. Ethrel rate depends on many factors, including cultivar and crop load. Refer to table on page 75.
Control ground suckers around base of trunk.
Tre-Hold A-112 Sprout Inhibitor. Also use herbicides approved for sucker control. See notes in Herbicide section (page 70-71) for Rely, Gramoxone.
++++
Use 10,000 ppm (10 oz/1 gal) as a low- pressure, large-droplet handgun application.
12
0
See Sucker Control (page 78) for specific recommendation details.
Delay preharvest fruit drop and delay fruit maturity.
ReTain
++++
Not more than one 333 g pouch
(50 g a.i.)
per acre
12
7
Single Pick Harvest. Applying one pouch of ReTain per acre 3 to 4 weeks prior to the anticipated beginning of the normal harvest period of untreated fruit will delay the harvest period by 7 to 10 days. Timing of ReTain application is critical. Apply ReTain closer to harvest in hot years. Use a 100% organosilicone adjuvant at a final concentration of 0.05 to 0.1% (v/v) in the spray tank for optimal response. Reduce the amount of a.i. per acre to 25 g on sensitive varieties such as Gala. Consult the label. Multiple Pick Harvest. Applying one pouch of ReTain per acre 1 to 2 weeks prior to the anticipated beginning of the normal harvest period of untreated fruit will improve quality and storage potential of later picked apples (2nd and 3rd pick fruit). Applications at this time will not typically delay the start of the harvest, but will help control the maturation rate of the later harvests.
22 Goals
Options
Relative1
Effectiveness (+)
or
Importance (*)
Amount per2
Re-entry
Interval
(hours)
Preharv.
Interval
(days)
Comments
100 gal
Acre
Delay or reduce preharvest fruit drop or both.
Preload NAA
(Fruitone-L or PoMaxa)
+++
2 oz
48
2
Make multiple applications of 5 ppm each week for the 4-week period prior to the normal start of the harvest period for each variety.
NAA
(Fruitone L or PoMaxa)
+++
8 to 32 fl. oz
48
2
Temporarily suppress any fruit drop by applying 10 to 20 ppm (depending on variety) of NAA. A second application can be applied 7 to 10 days later. See Growth-Regulating Chemicals section (page 73) for details.
ReTain plus NAA
(Fruitone L or PoMaxa)
+++++
One 333 g pouch of ReTain plus 8 to 16 fl. oz Fruitone L or PoMaxa per 100 gal per acre
12
7
Apply the ReTain plus Fruitone L or ReTain plus ProMaxa combination (plus adjuvant) as a tank-mix 2 weeks prior to the start of the normal harvest. This combination can provide improved fruit drop control and firmness retention compared to ReTain or NAA alone.
Reduce fruit russeting in susceptible varieties.
ProVide 10SG
Novagib 10L
(continue applications started at petal fall)
++++
++++
2.1 - 3.5 fl. oz
(60 to 100 g)
20 oz per acre/appl.
4
4
0
See Growth-Regulating Chemicals section (page 73) for recommendation details.
Reduce fruit cracking of susceptible varieties (e.g., Stayman).
Pro-Vide 10SG
+++
3.5 - 7.0 fl. oz
(100 - 200 g)
4
0
Make the first application at least 2 to 3 weeks before fruit cracking is likely to be observed in the orchard. Repeat at 14 to 21 day intervals until harvest. See Growth-Regulating Chemicals section (page 73) for details. Do not apply to trees that received ProVide applications for russet suppression.
Novagib 10L
+++
2 to 4 pt per acre/appl.
4
Promote lateral branching of current season’s growth.
Promalin
+++
0.8 oz/gal of
water (125 ppm)
12
None
See Growth-Regulating Chemicals section (page 73) for recommendation details.
1Effectiveness ratings range from + = poor control to +++++ = excellent control. Importance ratings range from * = minor importance to ***** = very important.
2Rates expressed as amount per 100 gal for dilute and amount per acre are for concentrate applications based on a tree-row-volume of 400 gal/acre.
23 SECOND COVER AND LATER SPRAYS (continued)
Goals
Options
Relative1
Effectiveness (+)
or
Importance (*)
Amount per2
Re-entry
Interval
(hours)
Preharv.
Interval
(days)
Comments
100 gal
Acre
Disease Management
Control summer diseases (white rot, black rot, sooty blotch, flyspeck, black pox).
Scout orchard.
Prune out fire blight strikes.
*****
*****
Apply cover sprays at 10- to 14-day intervals. Use a 7- to 10-day interval during wet, rainy periods. If thiophanate-methyl or a phosphite fungicide is not used in cover sprays, it is important to combine captan with sufficient ziram to increase fungicide rate to 8 to 10 lb/acre in order to control sooty blotch and flyspeck. Be sure to observe 77-day preharvest interval when using metiram or mancozeb. Use captan where there is a history of white rot.
Fungicides
Captan 50W
Captan 4L
Captan 80WDG
++++
++++
++++
1 qt
8 lb
4 qt
5 lb
24
24
24
0
0
0
Ziram 76DF
++++
6 lb
48
14
Sovran 50WG
++++
4 to 6.4 oz
12
30
A maximum of four applications and 25.6 oz of Sovran 50WG can be used per acre per season. It is weak on black pox.
Flint 50WG
+++++
1.5 to 2.5 oz
12
14
A maximum of four applications and 11 oz of Flint 50WG can be used per acre per season. For optimal control of white rot, tank mix with captan. Flint is weak on black pox.
Pristine 38W
+++++
14.5 to 18 oz
12
0
A maximum of four applications and 72 oz of Pristine can be used per acre per season. It is weak on black pox.
Thiophanate Methyl 85WDG
Topsin 4.5FL
Topsin M WSB
+++++
+++++
+++++
0.6 to 0.8 lb
15 to 20 fl oz
¾ to 1 lb
48
48
48
1
1
1
captan
50W or
4L or
80 WDG
+
mancozeb 75DF
+++++
3 lb
24
77
24
Goals
Options
Relative1
Effectiveness (+)
or
Importance (*)
Amount per2
Re-entry
Interval
(hours)
Preharv.
Interval
(days)
Comments
100 gal
Acre
Control summer diseases (continued).
Captan 80WDG
+
ProPhyt3
++++
3.75 to 5 lb
4 pt
24
4
0
0
Inspire Super 2.82EW
Rotated with:
Captan 80WDG
+
ProPhyt3
+++++
12 fl oz
3.75 to 5 lb
4 pt
12
24
12
14
0
0
This combination has provided good summer disease control. It is not especially effective on black pox, so if you use this program and have a history of black pox, begin the cover sprays with an EBDC+captan combination, or captan+thiophanate methyl, then switch to this program at 3rd cover. Do not make more than 5 applications (60 oz) of Inspire Super per year.
Aprovia
+++++
5.5 to 7 fl oz
12
30
Luna Sensation
++++
4 to 5.8 fl oz
12
14
Apply Luna Sensation in tank mixture with captan for optimal control of white rot.
Merivon
+++++
4 to 5.5 fl oz
12
0
Control Colletotrichum pathogens: Glomerella leaf spot/rot/Bitter rot.
Refer to fungicides used for Petal Fall and 1st cover applications.
Suppress necrotic leaf blotch on Golden Delicious.
ziram 76DF
zinc oxide 39.8%
+++++
+++++
6 lb
1 pt
48
0
14
0
Sprays from mid-June through early August are most important.
Control powdery mildew.
Scout orchard.
*****
Need for additional fungicides is based on the number of infections on newly unfolded leaves and continued growth pressure. See recommendations for petal fall if powdery mildew is present.
1Effectiveness ratings range from + = poor control to +++++ = excellent control. Importance ratings range from * = minor importance to ***** = very important.
2Rates expressed as amount per 100 gal for dilute and amount per acre are for concentrate applications based on a tree-row-volume of 400 gal/acre.
3Other phosphite fungicides are also labeled on apples. See the discussion of phosphite fungicides in the Fungicides and Bactericides section (p. 55).
25 SECOND COVER AND LATER SPRAYS (continued)
Goals
Options
Relative1
Effectiveness (+)
or
Importance (*)
Amount per2
Re-entry
Interval
(hours)
Preharv.
Interval
(days)
Comments
100 gal
Acre
Control Alternaria blotch.
Pristine 38W
+++++
14.5 to 18.5 oz
12
0
Make first application of Pristine around third or fourth cover (mid-June). Apply two additional applications at 10- to 14-day intervals. These applications will also control other summer diseases on Delicious. Rotations of Pristine and captan plus a phosphite fungicide are also effective and will help limit QoI fungicide use since only 4 applications are allowed by the label. Use in conjunction with a preventive mite management program. Do not make more than 4 applications or apply more than 72 oz of Pristine per season.
Control blister spot.
Fungicides
Aliette WDG
Phostrol
++++
++++
0.5 to 1 gal
2.5 to 5 pt
12
4
14
0
Fruit are most susceptible to blister spot 2 to 8 weeks following petal fall.
Insect Management
*****
See IPM practices for codling moth (page 34) and oriental fruit moth (page 36) to determine the need for and timing of insecticide sprays. Keep trap bottoms clean, and replace lures at recommended intervals.
The need for insecticides against codling moth should be based on pheromone trap captures and the degree-day model.
In orchards where mating disruption for codling moth and OFM is not being used, late season (late July and August) sprays of CheckMate OFM-F or application of Isomate OFM-TT is recommended for late season control of OFM. OFM populations often increase during August and September in apples.
Control codling moth and oriental fruit moth.
Monitor pheromone traps weekly for adult activity.
*****
Insecticides
(See First Cover.)
*****
OFM Mating Disruption
Isomate OFM-TT
CheckMate OFM-F
+++++
+++++
50-100 disp.
1 to 2 oz
26 Goals
Options
Relative1
Effectiveness (+)
or
Importance (*)
Amount per2
Re-entry
Interval
(hours)
Preharv.
Interval
(days)
Comments
100 gal
Acre
Control tufted apple bud moth.
Monitor pheromone traps weekly for adult activity.
Thin fruit to avoid excessive clustering.
*****
****
See IPM Practices for tufted apple bud moth (page 36) to determine the proper timing of insecticide applications.
Clustering of fruit is conducive to higher levels of tufted apple bud moth injury.
Insecticides
Intrepid
Delegate 25WG
Altacor 35WDG
Exirel 0.83SE
Belt 4SC
+++++
+++++
+++++
+++++
+++++
—
—
—
—
—
6 to 10 oz
4.5 to 7 oz
2.5 to 4.5 oz
8.5 to 17 oz
3 to 5 fl oz
4
4
4
12
12
14
7
5
3
14
Insecticide sprays for TABM are recommended only in orchards with a history of damage. See section on IPM practices for TABM (page 36) to properly time sprays. This spray often overlaps with the need for sprays of late-emerging codling moth.
Bacillus thuringiensis
Dipel 2X
CryMax
XenTari
+++
1 to 2 lb
1 to 2 lb
1 to 2 lb
4
4
4
0
0
0
For best results apply Bacillus thuringiensis (Bt) products at no less than 2X concentration. If using Bts, it is important to monitor codling moth with pheromone traps because Bts do not control CM.
Control apple maggot.
Erect red sticky spheres in early June to monitor adults.
****
Erect sticky traps baited with fruit essence lures on outside rows nearest abandoned orchards or other sources of flies. Check weekly. Threshold level is a cumulative of 5 flies per trap. If the threshold is exceeded again 2 weeks after spraying, apply again. Adults can emerge from June through September. Historically, peak emergence generally occurs from mid-July to early August.
Insecticides
Imidan 70WP
Admire 4.6SC
Assail 30SG
Surround WP
++++
++++
+++
+++
¾ lb
—
—
—
3 lb
2.8 oz
8 oz
20 to 50 lb
24
12
12
4
7
7
7
—
Apply Surround at 7- to 14-day intervals, or after a heavy rain, because thorough, uniform, and consistent coverage is important. Rate of Surround will vary with tree size.
1Effectiveness ratings range from + = poor control to +++++ = excellent control. Importance ratings range from * = minor importance to ***** = very important.
2Rates expressed as amount per 100 gal for dilute and amount per acre are for concentrate applications based on a tree-row-volume of 400 gal/acre.
27 SECOND COVER AND LATER SPRAYS (continued)
Goals
Options
Relative1
Effectiveness (+)
or
Importance (*)
Amount per2
Re-entry
Interval
(hours)
Preharv.
Interval
(days)
Comments
100 gal
Acre
Control white apple leafhopper or potato leafhopper.
Insecticides
Actara 25WDG
Admire 4.6SC
Assail 30SG
Sivanto 200SL
+++++
+++++
+++++
+++++
—
—
—
—
2 to 2¾ oz
2.8 oz
2.5 to 4 oz
7 to 10 oz
12
12
12
4
14
7
7
14
Threshold level for second brood white apple leafhopper nymphs (which occur in late July to early August) is one nymph per leaf. Treatment will eliminate the need to treat for adults immediately before harvest. Generally, low rates of insecticides will control leafhoppers.
Control brown stink bugs, including brown marmorated stink bug.
Insecticides
Actara 25 WDG
Belay SC
Danitol 2.4EC
Warrior 2.08CS
Endigo ZC
Leverage 2.7SE
+++
+++
+++
+++
+++
+++
4.5 to 5.5 oz
6 to 12 fl oz
16 to 21 fl oz
1.3 to 2.8 fl oz
5 to 6 fl oz
3.6 to 4.4 fl oz
12
12
24
24
24
12
35
7
14
21
35
7
Brown marmorated stink bug is established throughout apple production areas in NC, SC, and TN. It is in the early stages of infesting northeast GA. Expect infestations to be most common from August through mid-September.
*Check with local extension service for Section 18 labels that may be approved for BMSB.
Control spotted tentiform leafminer.
Insecticides
Delegate WG
Intrepid 2F
+++++
+++++
—
—
4.5 to 7 oz
8 to 12 fl oz
4
12
7
14
Leafminer infestations have become a rare occurrence in the past decade. A threshold level of two mines per leaf for second generation larvae (June to July), or 4 mines per leaf for third generation (August), should be used to dictate the need for STLM control.
Control green apple and spirea aphids.
Insecticides
Admire 4.6SC
Actara 25WDG
Assail 30SG
Belay
Sivanto 200SL
+++++
+++++
+++++
+++++
+++++
—
—
—
—
—
2.8 oz
4.5 oz
2.5 to 4.0 oz
4 to 6 fl oz
7 to 10 oz
12
12
12
12
4
7
35
7
7
14
Threshold level for green apple aphid is 50% infested terminals. Control is most important on young trees and in dwarf plantings. On mature trees, a higher threshold is tolerable. Biological control can often preclude the need for chemical control.
Control Comstock mealybug.
Insecticides
Diazinon 50WP
Actara 25WDG
Assail 30SG
Movento 2SC
+++++
+++
+++++
+++
1 lb
—
—
—
4 lb
4.5 oz
4 to 8 oz
6 to 9 fl oz
96
12
12
24
21
35
7
7
Applications should be made near the second or third cover spray. Comstock mealybug is an unpredictable pest, and orchards with a history of problems are most susceptible.
28 Goals
Options
Relative1
Effectiveness (+)
or
Importance (*)
Amount per2
Re-entry
interval
(hours)
Preharv.
interval
(days)
Comments
100 gal
Acre
Control woolly apple aphid.
Insecticides
Diazinon 50WP
Movento 2SC
+++++
+++
1 lb
—
4 lb
6 to 9 fl oz
24
12
21
7
Woolly apple aphid control can be difficult if insecticides are applied after populations reach large densities. Use a threshold of 10% infested shoots. Movento should be applied preventively in early July for best control. Also, an adjuvant must be used with Movento.
Control redbanded leafroller.
Insecticides
See insecticides for tufted apple bud moth.
Redbanded leafroller is a sporadic problem. If damage is done, it is usually by the last generation, which lays eggs from mid August to mid September.
Control lesser apple worm.
Insecticides
See insecticides for codling moth.
Lesser apple worm is a sporadic pest of importance in isolated areas. If damage occurs, it is usually by the third generation, which occurs in August.
Control dogwood borer.
Insecticides
Lorsban 50W
Lorsban 4E
++++
+++++
3 lb
1.5 qt
—
—
96
96
28
28
Apply insecticides with a handgun sprayer to the trunk, especially to burr knots and graft unions. Moths can lay eggs from mid-May through September, so treatment before July is optimal. Lorsban should be applied with a handgun sprayer from no more than 4 ft or with a shielded sprayer to prevent drift onto foliage or fruit.
1Effectiveness ratings range from + = poor control to +++++ = excellent control. Importance ratings range from * = minor importance to ***** = very important.
2Rates expressed as amount per 100 gal for dilute and amount per acre are for concentrate applications based on a tree-row-volume of 400 gal/acre.
29 SECOND COVER AND LATER SPRAYS (continued)
Goals
Options
Relative1
Effectiveness (+)
or
Importance (*)
Amount per2
Re-entry
Interval
(hours)
Preharv.
Interval
(days)
Comments
100 gal
Acre
Control European red mite and twospotted spider mite.
Monitor trees for mite activity.
*****
See IPM practices for European red mite (page 35). European red mite and twospotted spider mite threshold levels before July are 7 mites per leaf (85% infested leaves) and 10 mites per leaf (90% infested leaves) during July and August. If populations are near threshold level, check for predatory mites in 3 to 4 days to determine if biological control reduces mite populations. In orchards with Alternaria blotch, a threshold of 1 mite per leaf (50% infested leaves) should be used to minimize stress to trees.
Miticides
Acramite 50WS
Nexter 75WP
Portal 0.4EC
Apollo SC
Savey 50DF
Zeal 72WDG
Envidor 2SC
Kanemite 15SC
Nealta 1.67SC
wettable sulfur
summer oil
+++++
++++
++++
++++
++++
+++++
+++++
+++++
+++++
+
++
—
—
—
—
—
—
—
— —
1½ to 3½ lb
½ to 1 gal
¾ to 1 lb
4.4 oz
1 to 2 pt
4 oz
3 oz
2 to 3 oz
16 to 18 oz
21 to 21 fl oz
13.7 oz
5 to 15 lb
½ to 1% soln.
12
12
12
12
12
12
12
12
12
12
12
7
25
14
45
28
28
14
14
7
7
0
If Apollo or Savey was used at petal fall, do not reapply at this time. Do not expect complete control with a single application of oil or sulfur. These materials must be applied multiple times for best results. Applying a highly refined summer oil when mite populations are beginning to increase (first and second covers) will help suppress European red mite infestations. Do not apply captan 2 weeks before or after an oil spray.
Weed Management
Spot-treat with herbicide to control difficult-to-manage perennial weeds.
glyphosate
*****
++++
See Weed Response to Herbicide table
(pages 56 to 58).
4
1
Apple trees are especially sensitive to glyphosate applied in late summer and fall. Avoid contacting tree bark and especially foliage.
Bermuda grass control.
Poast
*****
++++
1.5 pt followed by
1 pt
12
14
Apply when Bermuda grass has 4 to 6 inches of new growth in spring. Follow with a second application when Bermuda grass has 4 inches of regrowth.
30 POSTHARVEST
Goals
Options
Relative1
Effectiveness (+)
or
Importance (*)
Amount per2
Re-entry
Interval
(hours)
Preharv.
Interval
(days)
Comments
100 gal
Acre
Plant Growth Regulators
Control fruit storage scald.
DPA
++++
2½ pt per one gal of water as a dip or spray to harvested fruit.
See Growth-Regulating Chemicals section (page 73) for complete details.
To maintain apple flesh firmness, fruit acidity and minimize scald.
SmartFresh
++++
See Growth-Regulating Chemicals section (page 73) for complete details.
Weed Management
In areas where heavy populations of winter annual weeds are present, apply herbicide as part of vole management program. Application of a fall preemergence herbicide will delay the spring herbicide application to early May or later.
Apply POST or PRE+POST herbicide.
See herbicide guide.
***
See herbicide guide.
See product labels.
1Effectiveness ratings range from + = poor control to +++++ = excellent control. Importance ratings range from * = minor importance to ***** = very important.
2Rates expressed as amount per 100 gal for dilute and amount per acre are for concentrate applications based on a tree-row-volume of 400 gal/acre.
31 32
Tree Row Volume (TRV):
A Model for Determining Spray Volume
The TRV model is a simple and objective method of determining (1) the volume of tree canopy on an acre of orchard, regardless of row spacing, tree size, age, or other factors; and (2) the dilute application water rate and chemical quantity for dilute (1X) applications or concentrate chemical load per acre needed to effectively spray each particular orchard, regardless of pruning and tree canopy density.
The TRV concept rests on these assumptions: Each row of trees is a wall of foliage, and water and chemical loads required can be related to the volume and density of foliage within that wall. Only three measurements must be made: (1) The distance between rows of trees; (2) the maximum tree height to be sprayed; and (3) the spread from drip line to drip line, which must be accurately measured to at least the nearest foot. In addition, an assessment of tree density is needed to calculate the TRV of an orchard.
Using these measurements, the TRV of any orchard can be calculated using the following formula:
Step 1:
Step 2: feet of row per acre (from Step 1)
x tree height (ft)
x cross-limb spread (ft)
= cu ft of foliage per acre.
Steps 1 and 2 determine the volume of foliage canopy per acre in the orchard.
Step 3: Select the number from Table 1 (below) that best indicates the canopy density of each separate orchard or block.
The cubic feet of foliage volume from Step 2 and the tree density established in Step 3 are used to calculate the water volume required per acre for a dilute spray application to provide maximum chemical load with a dilute airblast sprayer (applied to runoff).
Step 4:
cu ft of foliage
per acre
(from Step 2)
gallons of dilute solution to be applied per acre for a maximum application
canopy density
(from Step 3)
x
=
1,000 cu ft
Example:
Consider an orchard that has rows spaced 25 feet apart, trees 20 feet high, a spread of 17 feet from drip line to drip line, and a tree density of 0.85.
Step 1:
Step 2: 1,742.4 ft x 20 ft x 17 ft = 592,416 cu ft
Step 3: Density has been given as 0.85 gal/1,000 cu ft
Step 4:
However, general pesticide applications are not applied to runoff. Using 70 percent (0.70) of the “to runoff” calculated rate reduces the dilute application just to the point of drip, or what we call “pesticide dilute.” Table 2 (opposite) gives the adjustments to the “TRV calculated water rates for dilute to runoff” water application rate for various chemicals used and types of spray applications. The 503.5 gallons per acre in the example above is used to illustrate the adjustments in Table 2.
Table 1. Canopy density adjustments in tree row volume (TRV) model.
0.70 gal/1,000 cu ft
Trees extremely open, light visible through entire tree, less than 15 scaffold limbs per tree or young tree.
0.75 gal/1,000 cu ft
Trees very open, 18 to 21 scaffolds per tree, light penetration throughout tree, healthy spurs in tree canopy.
0.80 gal/1,000 cu ft
Trees well pruned, adequate light in trees for healthy spurs throughout trunk and scaffold limbs, many holes or openings in foliage where light is visible through tree.
0.85 gal/1,000 cu ft
Trees moderately well pruned, reasonable spur population within canopy, tree thick enough that light is not visible through bottom ⅔ of tree.
0.90 gal/1,000 cu ft
Trees pruned minimally, spurs inside canopy are weak due to limited light, very few openings where light is visible throughout the tree.
0.95 gal/1,000 cu ft
Little or no pruning, spurs dead or very weak in canopy, very little light visible throughout the tree.
1.00 gal/1,000 cu ft
Tree unpruned, extremely thick, no light visible anywhere through tree canopy, trees more than 20 ft high.
43,560 sq ft per acre
=
feet of row
per acre
distance between rows (ft)
43,560 ft2
=
1,742.4 ft
25 ft
592,416 cu ft
x 0.85 gal
=
503.5 gal per acre will apply a dilute application to runoff
1,000 cu ft 33
Table 2. Adjustments in tree row volume (TRV) calculated water rates per acre for various chemicals and spray applications.
Type of spray and chemical application
% of the calculated TRV dilute to runoff gallonage to be used for a dilute application
Actual gallons/acre to be used in previous TRV example orchard
1Pre-petal fall dilute pesticide application (adjusted because of incomplete foliage development)
56
282
Dilute pesticide application (from petal fall on and all other applications not specifically mentioned)
70
352
ProVide and Promalin (as a fine mist)
40 to 50
201 to 252
Spur Red Delicious thinners and dormant oil applications
100
504
Thinners for other varieties
70 to 90
352 to 453
Vegetative growth inhibitor
80 to 90
403 to 453
Preharvest Ethrel plus stop-drop spray
100 to 120
504 to 605
1To use this reduced gallonage requires accurate nozzling to top of trees and good air displacement within trees (i.e., reduced tractor speed).
Table 3 (below) demonstrates how the chemical load and water volume for concentrate sprays can be easily calculated from the TRV model.
The TRV model is accurate for dilute and concentrate chemical applications with conventional airblast sprayers, using water volumes as low as 150 gallons per acre. Below this gallonage, the physics of droplet size and impingement on the foliage can become a limiting factor in obtaining effective deposition on trees. Thus, if the TRV model calculates a water application rate of less than 150 gallons per acre, a 150 to 200 gallon rate should be considered a minimum in a conventional airblast sprayer, or be sure you are using a concentrate engineered sprayer (higher air speed) that will ensure adequate impingement of the spray solution on the tree surfaces at low water volume.
Table 3. How to calculate concentrate application rates.
Concentrate pesticide application
(3X water rate)1
Dilute pesticide TRV gallonage
=
352 gal/acre
=
117 gal/acre
Concentrate rate
3X
Concentrate pesticide chemical load per acre (2X to 4X)2
Rate of pesticide
per 100 gal
x
Dilute pesticide TRV
gal per acre
=
2.0 x 352
=
7.1 lbs/acre
100 gal
100
5X or greater3
Rate of pesticide
per 100 gal
x
Dilute pesticide TRV
gal per acre
x 0.8
=
2.0 x 352 x 0.8
=
5.6 lbs/acre
100 gal
100
1Assume the example orchard was to be sprayed at 3X concentration. 2Rate per 100 gal dilute. Example based on 2.0 lb pesticide/100 gal. 3This adjustment for concentrate application (5X or greater) should be made if spraying conditions are good and trees are properly matched to the sprayer. Adequate spray coverage cannot be assumed with concentrate application if sprays are applied during windy conditions or to thick, oversized trees.
Dwarf High-Density Orchards
Dwarf high-density orchards represent a special situation for TRV applications. Most high density orchard TRV water application rates calculate out at well below the minimum desirable gallonage for good droplet impingement (below 150 gallons/acre). We have consistently found improved efficacy of pesticide application and improved time efficiency by calibrating for double the TRV. This raises the water application rate above the minimum desirable gallonage, then you must drive every other row middle to reduce actual water volume per acre of orchard back to true TRV calculated rate. Pesticides are applied on a normal interval, alternating drive middles.
The reality of sprayer calibration and nozzling for chemical applications is that until the proper chemical load is appropriately delivered and deposited on leaf and fruit surfaces, the spray you apply cannot be considered an effective pesticide application. 34
IPM Practices for Selected Pests
Plum Curculio
Adults overwinter in leaf litter in and around orchards. In the spring when the daily maximum temperature exceeds 70°F, adults emerge, mate, and lay eggs under fruit skin. Adults generally begin to enter orchards shortly before bloom, with most adults present by the end of petal fall. Depending on weather conditions, new adults can continue to enter until at least the first cover spray. Damage is observed as feeding or oviposition scars and is cosmetic. Larval development can occur in apples that drop off the tree. Adult plum curculio are ¼-inch-long weevils with a curved snout; they are mottled black, gray, and brown with two bumps on each wing cover and a white marking across the back. Eggs hatch within a few days after being laid and feed in the fruit. The mature larva is ¼-inch long, white, slightly curved, and legless. The first generation adults usually emerge about 8 to 10 weeks later: late June or July depending on location. These adults will also feed on and damage fruit. Although plum curculio is capable of completing two generations per year in many southeastern locations, in most years only one is completed.
Scouting and Control: Plum curculio is very difficult to monitor, because traps are inconsistent and adults are difficult to observe and readily drop from trees when disturbed. After bloom, check twice weekly for plum curculio adults, feeding damage, and egg-laying scars. Typically, an insecticide at petal fall is sufficient for control, but occasionally emergence may be protracted under high population densities or cool conditions and a second application is necessary at first cover. A model developed in NY that predicts damage to apple by first generation adults is based on accumulating degree-days (50°F base, use codling moth degree-day table below) beginning at petal fall (90% of petals fallen) of ‘Delicious’ apples. The model predicts that insecticidal control is no longer necessary after 310 degree-days have accumulated from petal fall. First generation adults emerge and can feed on apples from late June through July, depending on location.
Apple Maggot
The apple maggot usually completes one generation per season, although a partial second generation can occur in certain years, particularly at elevations below 1,200 feet. Adult fly emergence from overwintering pupae in the soil is unpredictable and can occur from June through August, but the peak emergence is usually between mid July and early August. About 7 days after emergence, flies become sexually mature and mate, after which females deposit eggs under the skin of apples by puncturing them with their ovipositor. After a few days a small maggot hatches from the egg and the maggot tunnels within the fruit. When mature, the maggot exits the apple, drops to the ground, and burrows into the soil, where it completes development and forms a pupa. The pupa is the overwintering stage, and it emerges as a fly the following summer. If fly emergence is early in the season, some of their progeny emerge the same season rather than overwinter. In addition, a small percentage of flies may not emerge until 2 to 4 years later.
Weather conditions are important in dictating the timing and length of fly emergence. Pupae that are overwintering in lighter soils and in sunny areas emerge before those in heavier soils and shady areas. Sufficient soil moisture is also necessary for flies to emerge from soil-borne pupae. Drought delays or prevents many flies from emerging. Also, abandoned orchards (or even a few non-sprayed trees) and wild hawthorn trees adjacent to apples are potential sources of flies, and are a threat to commercial orchards located within a distance of about 400 yards.
Monitoring and Control: Monitor flies with red sticky spheres that are baited with a fruit essence lure. Baited spheres catch two to four times as many adults as non-baited spheres. In orchards with no history of maggot injury, a minimum of three red spheres should be placed on the outside row of an orchard closest to the suspected source of flies (e.g., abandoned orchard). Hang spheres in trees with fruit, and remove fruit within 18” of the sphere so that the sphere is highly visible to flies. In orchards with a history of damage, traps can also be placed in the interior of orchards on the southern side of trees. When using baited spheres, apply an insecticide after catching 5 flies cumulatively. Repeat an application at 14-day intervals if captures again reach 5 flies. Although the timing of emergence can vary among years, in most years the critical timing for insecticidal control is late July to early August.
Codling Moth
Codling moths begin to emerge and mate during April or early May, depending on location, and complete two generations per season. Depending on location and the year, a partial or complete third generation may occur, most commonly at elevations below about 1,000 feet. Eggs generally begin to hatch near the first cover spray, and soon larvae tunnel into and feed inside fruit. The mature larvae are similar to oriental fruit moth larvae, being ½-inch long and pinkish-white with legs. Unlike the OFM, codling moth larvae do not have an anal comb.
In recent years the codling moth has become a serious problem in orchards throughout the Southeast. Factors associated with problem orchards are (1) bin piles stored near orchards and/or (2) insecticide-resistant populations. Bins are an ideal environment for overwintering larvae, and when they complete their development the following spring the adults disperse to nearby orchards. Orchards within 100 to 150 yards of bin piles are particularly prone to infestation. Insecticide resistance has been detected in a number of orchards where problems have persisted for one or two years.
Codling Moth Degree-Day Model
The codling moth degree-day model is used to predict adult emergence and egg hatch of each of the two to three 35
generations that occur each year. The model has been in existence for more than 30 years and was recently modified to more accurately reflect southeastern populations. However, the model may not be accurate where moths emerging from nearby bins are a primary source of codling moth, because these individuals usually emerge later than those in natural habitats in the orchard.
Base a decision to spray insecticides against codling moth on pheromone trapping and the codling moth degree-day model. Use pheromone traps to determine the starting point of the model (biofix) and to gauge the intensity of populations. The degree-day model predicts percent of adult emergence and egg hatch for each of the two to three generations of codling moth that annually occur in the Southeast. The model is quite accurate for the first generation, but is less accurate for each successive generation.
To use the model, begin to accumulate degree days when male flight begins in the spring, which is referred to as biofix. The biofix date is determined with pheromone traps to detect the first sustained catch of two or more moths in the spring. Traps should be placed in orchards near the tight cluster stage of bud development, and checked one to two times per week. Hang traps at a density of one trap per 10 acres of orchard. Traps hung in the upper third of the canopy catch more moths than those in the lower canopy and are a preferred location. Once biofix is determined, degree days are calculated daily. It is only necessary to check traps once per week after biofix is determined. Use the table on page 39 to determine the number of degree days occurring at various maximum and minimum daily temperatures.
First Generation CM: Recommendations are provided for low- and moderate-to-high population densities. Low-density orchards are those where less than 0.2 percent of fruit were damaged the previous year and pheromone trap catches do not exceed 1 to 2 moths per trap per week anytime during the first generation (up to about 1000 DD after biofix). Under these conditions, a single application at 350 DD after biofix is sufficient.
In moderate-to high-density orchards, apply two insecticide applications at 14 to 21 days apart, the first at 100 to 250 DD after biofix: 100 to 150 if using a product which depends primarily on ovicidal activity for control (i.e., Intrepid or Rimon), and 250 if using other insecticides that target early stage larvae. Additional applications may be necessary if trap captures remain high (greater than 7 moths per trap).
A second emergence of overwintering adults sometimes occurs between 500 and 800 degree days after biofix. This is often referred to as the “B peak” and may be associated with insecticide-resistant individuals in the population. Hence, pheromone trapping is important throughout the flight period.Relationship between degree-day accumulations from biofix and percentages of codling moth adult emergence and egg hatch.
Cumulative
Degree Days
% Adult Emergence
% Egg
Hatch
0 (Biofix)
5
0
1
10
0
50
13
0
100
17
0
150
22
0
200
29
0
250
36
0
300
43
0
350
52
3
400
60
8
450
67
12
500
74
22
550
80
30
600
84
36
650
88
42
700
91
54
750
93
62
800
95
64
850
96
67
900
97
73
950
98
81
1000
99
92
1050
10
100
1100
12
1
1150
15
1
1200
19
2
1250
23
3
1300
28
4
1350
33
5
1400
39
8
1450
45
11
1500
51
15
1550
57
20
1600
63
24
1650
69
29
1700
74
35
1750
78
38
1800
82
48
1850
86
64
1900
88
65
1950
91
68
2000
93
71
2050
94
73
2100
95
75
2150
96
78
2200
97
81
2250
98
84
2300
98
84
2350
99
85
2400
99
90
2500
10
95
2550
15
98
2600
20
99
2650
25
100
36
Second generation CM: Recommendations are provided for extremely low, low, and moderate-to-high population densities. Extremely low-density orchards may not require an insecticide application (no first-generation damage is observed and pheromone trap catches remain below one moth per trap per week between 1,000 and 2,500 DD after biofix). Low-density orchards require one insecticide application, and recent research indicates the optimum timing is 1,400 to 1,500 DD. These orchards may have no sign of damage by first generation larvae and trap catches between 3 to 5 moths per trap per week between 1,000 to 1,500 DD after biofix. Moderate-to high-density orchards will have fruit damage and higher pheromone trap catches requiring at least two insecticide applications at 14-day intervals, starting about 1,400 DD after biofix, and additional applications if trap captures remain above 5 to 7 moths per trap per week.
Third Generation CM: The model should not be relied upon alone for timing insecticide applications for the third generation, because the model becomes less accurate over time.
Exceptions to the Model: Where codling moth populations are extremely high and where pheromone trap catches remain high between generations, additional insecticide applications at shorter intervals may be necessary. This often occurs in orchards adjacent to abandoned orchards, orchards near bins, or in problem orchards with high populations.
Oriental Fruit Moth
Oriental fruit moths begin to emerge and mate before apple bloom, and eggs begin to hatch at petal fall. Variable spring temperatures cause erratic emergence and egg-laying by first-generation moths. The larvae feed on shoot tips and inside apple fruit. The mature larva is ½-inch long, pinkish-white, and has an anal comb and legs. The only way to distinguish between oriental fruit moth and codling moth larvae is to use a hand lens to examine mature larvae for the presence of an anal comb. Codling moth larvae do not have an anal comb.
Oriental Fruit Moth Degree-Day Model
Base a decision to spray insecticides against oriental fruit moth on pheromone trap catches and a DD model. The model biofix is determined in the same manner as for the codling moth. Use pheromone traps to determine the starting point of the model and to gauge the intensity of populations. The degree-day model predicts adult emergence and egg hatch for the first three of the four or five generations that occur in the Southeast. However, generations overlap later in the season, which makes the degree-day model less useful at this time. The table on page 39 uses daily maximum and minimum temperatures to determine daily DDs for oriental fruit moth (base 45°F). Place traps in the orchards near the green-tip stage of bud development, and check one to two times per week. Hang traps at eye level at a density of 1 trap per 10 acres of orchard. Check traps weekly after the biofix date.
First-Generation OFM: Control of the first generation is often important to prevent first-generation damage and to reduce populations of subsequent generations. First-generation egg laying is usually low on apple, and only one insecticide application between 400 and 500 DD after biofix is necessary, which usually coincides with petal fall.
Second-Generation OFM: If first-generation control was successful, second-generation populations are usually very low. Extremely low-density orchards may not require an insecticide application (pheromone trap catches never exceed 3 moths per trap per week between 800 to 1,600 DD). In low-density orchards (3 to 5 moths per trap per week between 800 and 1,500 DD), make a single insecticide application at 1,400 DD. Moderate- to high-density orchards will have fruit damage, higher trap catches, or both, and may need two insecticide applications 14 days apart starting at 1,100 DD.
Third and Fourth Generations: Use of the degree-day model becomes less useful beginning in July and August due to overlapping of generations. For this reason, rely on pheromone trap captures to determine the need for control measures. Use of a threshold level of 7 moths per trap per week has worked well to minimize damage. In situations where consistently high trap captures occur, mating disruption should be considered (see below).
Tufted Apple Bud Moth
The tufted apple bud moth (TABM) is the most common leafroller occurring on apple in the Southeast. In the 1990s it was the most destructive insect pest of southeastern apples due to insecticide resistance, but populations have greatly reduced since the introduction of new insecticides in the early 2000s. TABM completes two generations per year, with egg laying occurring during June (first generation) and August and September (second generation). Larvae feed on leaves and fruit, with fruit damage usually observed as surface feeding. However, second-generation larvae may also be found feeding within the calyx end of fruit. Unless an individual orchard has a history of damage by this insect, it is doubtful that special precautions need to be taken. Timing is critical to the successful management of this pest. In most instances, one well-timed insecticide application per generation will provide high levels of control. Cultural controls are also important. Maintain a clean orchard floor, particularly in the early spring before bloom, to minimize TABM populations by removing the food source for overwintering larvae. New apple sucker growth and broadleaf weeds are important food sources in the spring. Thinning apples to breakup clusters of fruit also reduces damage.
Tufted Apple Bud Moth Degree-Day Model
A TABM degree-day model similar to that of the oriental fruit moth and codling moth was developed specifically for populations in the Southeast. For calculating degree days from maximum and minimum daily temperatures, use the oriental fruit moth table on page 39 (45°F). Place TABM pheromone traps at the tight cluster to pink stage of bud development at a density of 1 trap per 20 acres of orchard. Biofix is the first date on which a sustained catch occurs and may vary from 2 to 5 moths per trap per week. The cumulative number of degree days from the point of biofix is used 37
to predict percent egg hatch and to time insecticide applications against the first generation.
First-Generation Recommendation: When population densities are sufficiently high or if a short residual insecticide is used (i.e., Bacillus thuringiensis), two insecticide applications per generation may be necessary; make the first application at about 10 percent egg hatch, which occurs at about 800 DD after biofix, and the second application 14 days later. Where populations are low or if using a long residual insecticide (Intrepid, Delegate, Altacor), one application per generation should be made anytime between 10 and 30 percent egg hatch of the first generation, or from 800 to 1,200 DD after biofix.
Second-Generation Recommendation: Population densities of second generation TABM have been low since the registration of highly effective new insecticides such as Altacor, Intrepid, Delegate, and Rimon. In fact, insecticidal control of the second generation has not been necessary in many orchards when one of these products was used against the first generation. Not unless pheromone trap captures exceed about 15 moths per trap by 2,600 DD after biofix (time of 10% egg hatch of the second generation) is an insecticide application recommended. Control is most important on later maturing apples that are harvested after mid September.
Mating Disruption
Mating disruption consists of emitting relatively large amounts of an insect’s sex pheromone into an orchard environment to disrupt the normal mate-location process. Mating disruption prevents or reduces mating and the subsequent laying of fertile eggs, which effectively reduces populations below economically damaging levels. It is effective only in blocks of 5 acres or more. In apples, mating disruption is registered for codling moth and oriental fruit moth. Oriental fruit moth is much easier to control with mating disruption compared with codling moth; use both mating disruption and insecticides against moderate to high codling moth populations. Mating disruption will not control infestations resulting from immigrating fertilized female moths; hence, mating disruption alone is not recommended in blocks located adjacent to a likely source of immigrating moths (such as abandoned orchards or bin storage areas).
Pheromone Dispensers: A number of companies market pheromone dispensers for mating disruption, including hand-applied dispensers that emit pheromones for a relatively long period and sprayable products that last for shorter periods and need to be reapplied. Companies are now marketing pheromone dispensers that contain both codling moth and oriental fruit moth so that a single dispenser type can be used for mating disruption of both insects. Dispensers vary in the amount of pheromone they contain and the length of time during which pheromone is emitted, so read the label beforehand to ensure that dispensers are used properly. Because both codling moth and oriental fruit moth are potential pests in the Southeast, it is highly recommended that dual pheromone dispensers be used in apples.
Timing of Applications: For the codling moth, place pheromone dispensers in the orchard before adults begin to fly in the spring. First emergence of adults usually begins during late bloom or petal fall of Delicious cultivars. Hence, dispenser application should be completed by petal fall. Best results are obtained when dispensers are hung in the upper third of the canopy, because this is where mating occurs.
The oriental fruit moth begins to emerge near green tip of Delicious cultivars, so for season-long control, dispensers should be in the orchard by this time. However, insecticides applied at petal fall for other insects usually control this first generation, so if using oriental fruit moth dispensers only, application can be delayed until just before emergence of the second- or third-generation adults (950 and 1850 DD after biofix, respectively). If using sprayable pheromones for mating disruption, which is only recommended for OFM, make the initial application when hand-applied dispensers are applied. If mating disruption is not used against this insect and pheromone trap captures remain low during the season, a single late-season application in mid to late August will help to suppress late-season populations.
Monitoring Insects: Monitoring codling moth and oriental fruit moth populations is of critical importance to measure the effectiveness of mating disruption and to determine the need for insecticides. Pheromone traps should be used to monitor moth populations, and fruit should also be examined at periodic intervals. When properly used, pheromone trapping can be useful to determine the need for insecticides under mating disruption orchards. Traps should be hung in the upper one-third of the canopy, because that is where codling moth activity is most intense. Traps should be hung at a density of no less than one trap per five acres, and preferably one per three acres, and checked at weekly intervals. Trap captures should be added each week, and when the cumulative number exceeds an average of three moths per trap, an insecticide may be necessary. Threshold levels are based on using large delta-style traps and Trece CM L2 lures, which should be replaced at 12-week intervals.
The type of pheromone lure used in traps is also important. Some lures contain a pear ester kairomone that enhances capture of codling moth and may capture female moths, and is sold as CMDA. Lures to enhance OFM captures contain a combination of OFM pheromone plus codling moth. Finally acetic acid lures placed in traps with the pheromone lures enhance capture of both moths.
European Red Mite Management
Several beneficial arthropods can help keep European red mite (ERM) populations below damaging levels. The most common in the Southeast are the phytoseiid mite (Amblyseius fallacis) and a complex of generalist predators (such as lady beetles and lacewings). However, recent research in North Carolina suggests that neither of these predators overwinters to any significant degree within orchards, so they must be reestablished in orchards in the spring. Hence, practices that delay the buildup of ERM and enable predators to increase before mites become a problem will favor biological control. The two most effective practices 38
are applying a delayed dormant oil spray and avoiding insecticides toxic to these predators.
Monitoring Mite Populations: Use a regular monitoring program to follow the buildup of mite populations and to determine if and when supplemental applications of a miticide are necessary to avoid economic damage. Monitor each contiguous block of apples weekly beginning when adult mites
first appear (which may vary from mid-May to late June). Within each block, examine 5 leaves from each of 10 trees with a visor lens or hand lens. Rather than counting the total number of mites on each leaf, record the number of leaves infested with one or more mites, and estimate mite density from the table below.
Determining the Need for Miticides: When mite populations reach a density of 5 to 10 mites per leaf (80 to 90 percent infested leaves), decide whether to rely on biological control or apply a miticide to prevent mites from increasing to damaging levels. To gauge the potential for biological control with predator mite A. fallacis, count the number of predator mites on sample leaves with a visor lens. If the ratio of A. fallacis to ERM is between 1 to 5 and 1 to 15, biological control is possible. If predators are not present and mite populations are between 5 to 10 mites per leaf, apply a miticide.
Where Alternaria blotch is a problem on Delicious apples, biological control is usually not an option. Alternaria blotch in the presence of mite injury can lead to premature defoliation, so mite populations must be maintained at very low levels. If preventive control measures are not used, miticides should be used when mites reach 1-2 mites per leaf.
Relationship between European red mite density per leaf and % infested leaves.
% Mite-Infested Leaves
(>1 mite/leaf)
Expected No.
Mites per Leaf
40
45
50
55
60
65
70
75
80
85
90
95
0.7
0.9
1.1
1.3
1.6
2.0
2.6
3.4
4.7
6.8
11.4
26.4 39
Codling moth degree days (50°F lower base, 88°F upper base) at various daily maximum and minimum temperatures.
Max
54
56
58
60
62
64
66
68
70
72
74
76
78
80
82
84
86
88
90
92
94
96
Min
20
0
1
1
2
2
3
3
4
5
5
6
7
8
9
9
10
11
12
13
14
15
15
22
0
1
1
2
2
3
3
4
6
6
6
7
8
9
10
10
11
12
13
14
15
15
24
0
1
1
2
2
3
4
4
6
6
7
7
8
9
10
11
11
12
13
14
15
16
26
0
1
1
2
2
3
4
4
6
6
7
7
8
9
10
11
12
12
13
14
15
16
28
0
1
1
2
2
3
4
4
6
6
7
8
8
9
10
11
12
13
14
15
15
16
30
0
1
1
2
2
3
4
5
6
6
7
8
9
10
10
11
12
13
14
15
16
16
32
0
1
1
2
3
3
4
5
6
6
7
8
9
10
11
11
12
13
14
15
16
17
34
0
1
1
2
3
3
4
5
6
7
7
8
9
10
11
12
13
14
14
15
16
17
36
0
1
1
2
3
4
4
5
6
7
8
8
9
10
11
12
13
14
15
16
17
17
38
0
1
1
2
3
4
4
5
6
7
8
9
10
11
11
12
13
14
15
16
17
18
40
0
1
2
2
3
4
5
6
6
7
8
9
10
11
12
13
14
15
16
17
17
18
42
0
1
2
2
3
4
5
6
7
7
8
9
10
11
12
13
14
15
16
17
18
19
44
0
1
2
3
3
4
5
6
7
8
9
10
11
12
13
14
15
15
16
17
18
19
46
0
1
2
3
4
5
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
48
1
2
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
20
50
1
2
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
52
2
3
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
54
-
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
56
-
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
58
-
-
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
60
-
-
-
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
62
-
-
-
-
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
64
-
-
-
-
-
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
66
-
-
-
-
-
-
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
68
-
-
-
-
-
-
-
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
70
-
-
-
-
-
-
-
-
18
19
20
21
22
23
24
25
26
27
28
29
30
31
72
-
-
-
-
-
-
-
-
-
20
21
22
23
24
25
26
27
28
29
30
31
32
74
-
-
-
-
-
-
-
-
-
-
22
23
24
25
26
27
28
29
30
31
32
33
76
-
-
-
-
-
-
-
-
-
-
-
24
25
26
27
28
29
30
31
32
33
34
Oriental fruit moth degree days (45°F lower base, 91°F upper base) at various daily maximum and minimum temperatures.
Max
50
52
54
56
58
60
62
64
66
68
70
72
74
76
78
80
82
84
86
88
90
92
94
96
Min
20
1
1
2
2
3
4
4
5
6
7
8
9
9
10
12
12
13
14
15
16
17
17
18
19
22
1
1
2
2
3
4
4
6
7
7
8
9
10
11
12
12
13
14
15
16
17
18
18
19
24
1
2
2
2
4
4
5
6
7
7
8
10
10
11
12
12
14
15
15
16
18
18
19
20
26
1
2
2
3
4
5
5
6
7
7
8
10
10
11
12
13
14
15
16
16
18
18
19
20
28
1
2
3
3
4
5
5
6
7
8
9
10
10
11
13
13
14
15
16
17
18
19
20
20
30
1
2
3
3
4
5
5
6
7
8
9
10
10
12
13
13
15
16
16
17
19
19
20
21
32
1
2
3
3
4
5
6
6
8
8
9
10
11
12
13
14
15
16
17
18
19
19
20
21
34
1
2
3
3
4
6
6
7
8
8
10
11
11
12
14
14
15
17
17
18
19
20
21
21
36
1
2
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66
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68
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70
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39 40
Pesticide Resistance Management
General Considerations
Pesticide resistance is a shift in the genetics of a pest population that allows individuals within a previously susceptible population to survive. Resistant pest populations have inherited traits that reduce their susceptibility to individual pesticides or groups of pesticides. Resistance develops in all agricultural pest groups—insects, mites, fungi, bacteria, nematodes, and weeds. Pesticide-resistant individuals are initially quite rare in pest populations. However, when a new pesticide is first used, a very low number of individual pests never previously exposed to the novel chemistry can be expected to be resistant. The frequency of resistant genes to novel chemistries varies tremendously, but history makes it clear that resistant individuals should be expected in all pest groups. By the nature of the process, resistance most often develops to pesticides that are initially very effective and frequently used.
Pesticide resistance management is an effort to slow or prevent the development of resistance. It relies on pest management and pesticide-use strategies to prolong the effective life of pesticides. Resistance management is difficult, especially in high-value crops such as fruit, where high quality standards and limited numbers of registered pesticides make the task more challenging.
Managing resistance requires an understanding of the factors that influence its development. Selection is the process of pesticide-induced selection for resistance. With regular pesticide use, those rare individuals that are naturally resistant survive and reproduce more successfully than their susceptible peers. Resistance frequency refers to the proportion of a pest population that is resistant. Cross resistance refers to a type of resistance in which a pest population develops resistance to more than one pesticide within a chemical family (such as organophosphate insecticides or EBDC fungicides). Multiple resistance involves multiple, independent resistance mechanisms, which often lead to resistance to chemicals from different families (organophosphate and carbamate insecticides, dodine and DMI fungicides). Resistance stability is a key factor in managing resistance. Stability is an estimate of how well resistance persists in a pest population once the pesticide is no longer used. The rate of reversion to a susceptible state varies enormously. But when pesticide use ceases, selective pressure for resistance is removed, and over time resistance will often be reduced. Resistance stability estimates may allow limited use of resistance-prone compounds.
It is important to emphasize that control failures do not confirm resistance. Other factors (poor timing, sprayer calibration or coverage, wash-off, high pH in spray tank water, inappropriate materials, etc.) should be eliminated as causes for control failures before resistance is seriously considered. Factors influencing the development of resistance can be grouped into biological and management categories. Biological factors include pest reproductive rate, mobility of the pest species into and out of untreated areas, and genetic factors such as number of resistance mechanisms, resistance frequency and intensity, and resistance stability. Management factors that influence resistance development include how materials are applied, how often they are used, how long they persist in the field, treatment thresholds, and strategies for using available pesticides. Resistance management efforts study specific pest-pesticide interactions and focus on practical strategies that growers can implement.
Pest management is practical and works in concert with pesticide-use strategies to lessen resistance selection by facilitating prudent, as-needed pesticide use. Pesticide-use strategies work best when implemented as a new pesticide comes into commerce. Pesticide manufacturers, IPM scientists, and growers have come to recognize that using resistance management from the beginning works best. Collecting baseline susceptibilities, defining probable resistance problems beforehand, and proposing pesticide-use strategies to forestall resistance development are the province of manufacturers and IPM scientists. Biologically and economically sound resistance management plans offered pre-sale give growers the best hope for managing resistance. Pesticide-use strategies are often grouped as follows: (1) management by moderation, (2) rotation and mixtures, and (3) saturation.
Moderation means limiting the use of a pesticide. Moderation is employed in concert with IPM practices, such as using treatment thresholds, spraying only specific pest generations or growth stages, maintaining unsprayed wild host reservoirs to act as refuges for genetically susceptible individuals, using pesticides with shorter residual or lower toxicity to important beneficial populations, etc. Moderation should be used to the fullest extent that will provide commercially acceptable control.
Rotation, and in some cases mixtures, are the bulwarks of pesticide-use strategies because an individual pest is less likely to be resistant to two or more differing classes of toxins. In theory, most individual pests resistant to one pesticide will be killed when exposed to a different class of toxin. Rotations depend on having effective, labeled materials with different modes of action. Material cost is a key practical consideration that favors rotation. Mixtures of fungicides have been used successfully to combat disease resistance, although cost lessens the attractiveness of this approach. Mixtures of insecticides and miticides have typically performed poorly. Rotation is seen as the desired approach for insecticides, miticides, and some fungicides.
Saturation, the use of higher pesticide rates to control resistant individuals, is the least attractive resistance management approach, although it has been used to manage resistance to DMI fungicides. Saturation is generally a last resort when there are no other effective, labeled alternatives. In this scenario, higher rates will often provide control for a time, although at greater cost. Synergists, chemicals that increase the toxicity of pesticides, have sometimes been effective in boosting the efficacy of resistance-prone pesticides. As with simple rate increases, saturation with synergists typically provides only short-term benefits.
41
Insecticide Resistance Management Strategies
In the southeastern United States, pesticide resistance has been documented in the tufted apple bud moth, codling moth, rosy apple aphid, and European red mite. Currently, codling moth resistance is most important, but good resistance management strategies are required to prevent other pests from developing resistance.
Codling Moth
Insecticide-resistant codling moth populations became prevalent throughout the Southeast in the early 2000s. Resistance to one or more registered insecticides, including Intrepid and Rimon, were detected in a number of orchards in Georgia and North Carolina. In situations where codling moth resistance occurs, populations usually increase to large numbers, and frequent insecticide applications at short intervals (7 to 10 days) are necessary at critical times (between 400 and 800 DD after biofix) to prevent damage. However, such intense insecticide use may lead to higher levels of resistance, so alternative management strategies should be used in conjunction with insecticides. Using mating disruption is strongly encouraged as a resistance management tactic, because this will help reduce population densities more quickly than insecticides alone and, subsequently, the need for insecticide applications. After two to three years of continuous mating disruption, codling moth population densities can be reduced so that only one or two total insecticide applications are needed for season-long control. In addition, make an attempt to avoid using more than two insecticide applications against a single codling moth generation by incorporating codling moth virus (Cyd-X or Carpovirusine) applications into the spray program after two applications have been made. When choosing insecticides, rotate insecticides with different modes of action against each generation. For example, make two applications of the same insecticide against the first generation, but use an insecticide with a different mode of action against the second generation.
Rosy Apple Aphid
The rosy apple aphid has developed widespread resistance to Lorsban, and control failures with Asana, Ambush, Danitol and Diazinon have become more common in recent years. Consequently, neonicotinoid insecticides are now most commonly used for control. It is important to remember that all neonicotinoids (Actara, Assail, Calypso, Belay, and Provado) have a similar mode of action and should be considered the same material for rotation purposes.
The two best times to control rosy apple aphid on apple are (1) tight cluster to pink or (2) petal fall. Do not apply any insecticide with the same mode of action more than once during this time frame, and if possible do not use the insecticide used for rosy apple aphid control more than once during the period when the aphids may occur in apple orchards (through the third or fourth cover spray).
European Red Mite
Avoiding unnecessary miticide applications is the most effective strategy for minimizing the potential for resistance development. A delayed dormant oil application is highly recommended to suppress overwintering populations of European red mite and to improve the potential for biological control to maintain mite populations below damaging levels. On Delicious cultivars, which are susceptible to Alternaria blotch and where preventive control or low threshold levels are recommended for control of European red mite, there is a high potential for developing resistant populations. To reduce this potential, in addition to a delayed dormant oil application, do not use the same miticide in successive years.
Resistance Management Strategies for Plant Pathogens
Resistance of plant pathogens to pesticides has become widespread over the past 40 years as site-specific (systemic) chemicals have been developed and used on many crops and against many pathogens. The broad-spectrum protectants (such as captan and mancozeb) that were used previously had multiple sites of activity in the target pathogens, greatly reducing the likelihood of resistance development.
Resistance has become a problem in the U.S. in at least five pathogens that affect apples during the growing season: Venturia inaequalis, cause of apple scab; Podosphaera leucotricha, cause of powdery mildew; Alternaria mali, cause of Alternaria leaf blotch; Erwinia amylovora, cause of fire blight; and Pseudomonas syringae pv. papulans, cause of blister spot. Resistance of V. inaequalis to dodine (Syllit, initially sold as Cyprex) was first reported in New York in 1969. It has subsequently been reported in several states in the Northeast and Midwest but has not been found in orchards in the Southeast. Resistance of V. inaequalis to the benzimidazole fungicides (benomyl and thiophanate-methyl) was reported shortly after their introduction in 1971 and became widespread in the eastern U.S., including the Southeast, in the mid-1970s. As a consequence they are no longer recommended for apple scab control in the Southeast. The demethylation inhibiting (DMI) fungicides were first introduced in the late 1980s, and reduced sensitivity of V. inaequalis has been reported or suspected in a number of orchards in the Northeast and Midwest. Some growers in NC have also had problems controlling scab with DMI fungicides, suggesting that resistance may be a problem here as well. Resistance of V. inaequalis to strobilurin (QoI) fungicides (Flint and Sovran) has been reported in Virginia. Resistance of Alternaria mali to the QoI fungicides (Flint and Sovran) has been reported in North Carolina. Resistance of Podosphaera leucotricha to EBI and QoI fungicides is evident in Virginia. Resistance of the fire blight bacterium, E. amylovora, to streptomycin (FireWall, Agri-mycin 17, Streptrol) is present in several states but has not been reported in the Southeast. Resistance of P. syringae pv. papulans has been confirmed in an orchard in Tennessee and in New York. There is potential for resistance to the Group 9 fungicides (anilinopyrimidine, AP, cyprodinil, and pyrimethanil), which include Vangard and Scala and are components of Inspire Super and Luna Tranquility, and to the newer Group 7 42
fungicides (carboximide, SDHI, boscalid, fluopyram, fluxapyroxad, and penthiopyrad), which are included in Pristine, Luna Sensation, Luna Tranquility, Merivon, and Fontelis.
To avoid resistance development, minimize the use of fungicides and bactericides in which resistance is likely to develop. Additionally, combine site-specific fungicides with protectant fungicides that have broad spectrum activity. Limit
dodine applications to two to three per year. In areas where dodine resistance first became a problem, it was often used 10 to 12 times throughout the growing season. Similarly, limit streptomycin use for fire blight control to two to four times a year. Make applications only during times favorable for infection. These periods are characterized by open blossoms, dew or rainfall greater than 0.01 inch, an average daily temperature of 60°F or greater, and the accumulation of at least 198 degree-hours greater than 65°F since the first blossoms opened. Use the DMI and QoI fungicides only in combination with broad spectrum protectants, such as captan or EBDC fungicides. Avoid post-symptom applications of site-specific fungicides, such as dodine and the DMI fungicides, because this sets up an ideal situation for selection of resistant strains. Good orchard sanitation practices to maintain pathogen populations at low levels are also an important component of a resistance management program.
Herbicide Resistant Weeds
The reality of herbicide resistant weeds infesting orchards is more likely today than ever. Populations of pigweed and goosegrass resistant to dinitroanaline herbicides (Prowl and Oryzalin) exist in the Southeast. Populations of johnsongrass resistant to carboxylase herbicides (Fusilade DX) also have been documented. Most recently glyphosate resistant weeds have been found across the Southeast and Midwest. Glyphosate resistant weed populations have been verified in Delaware, North Carolina, South Carolina, Georgia, and Tennessee. The two most notable species developing resistance to glyphosate are horseweed and Palmer amaranth. Glyphosate resistant ragweed is suspected and being investigated as well. Growers should be aware that these weeds are in apple production regions and in the event of control failures herbicide programs will have to be altered. If you suspect a problem or need additional information you should contact your county agent with the Cooperative Extension Service.
In order to prevent the development of herbicide resistant weeds growers should take into consideration the following practices:
1. Rotate herbicides with different modes of action (see table below). For example, do not use simazine (Princep, Simazine) continuously. Consider other pre-emergence broadleaf herbicide options. Avoid making more than two applications of the same herbicide in the same year.
2. Scout orchards to identify weeds. Respond quickly to changes in weed populations by controlling weeds
before they spread throughout the entire orchard.
3. Use non-selective post-emergence herbicides in a weed management program.
4. Use herbicides only as needed.
Herbicide Mode of Action Table
MOA Group
Herbicide Members
1
Clethodim (Select, etc.), Fluazifop (Fusilade), Sethoxydim (Poast)
2
Rimsulfuron (Matrix, Pruvin, Solida) and Halosulfuron (Sandea)
3
Oryzalin (Surflan) and
Pendimethalin (Prowl)
4
2,4-D amine, clopyralid (Stinger), fluroxypyr (Starane or Comet)
5
Simazine and Terbacil (Sinbar)
7
Diuron (Karmex, Direx)
9
Glyphosate (Roundup, etc.)
10
Glufosinate (Reckon)
12
Norflurazon (Solicam)
14
Flumioxazin (Chateau), Carfentrazone (Aim, Zeus Prime), Salflufenacil (Treevix), Sulfrentrazone (Zeus Prime)
20
Dichlobenil (Casoron)
22
Paraquat
(Gramoxone, Firestorm, Parazone)
29
Indaziflam (Alion) 43
Effect of pH on Pesticide Activity
Although the pH of spray water does not directly affect resistance development, it can affect the activity of some pesticides. The label on dimethoate, phosmet, malathion, azinphos-methyl, formetanate, ethephon, NAA, and possibly others warns of this effect. When these materials, except NAA, are exposed to a pH above 7.5, they undergo hydrolysis and break down to products that are either less effective or not effective. Excessively acidic conditions may limit uptake of NAA and, therefore, its effectiveness. The actual rate of breakdown depends on solubility and temperature and the total quantity broken down during a given period. For example, captan is hydrolyzed very quickly at alkaline pHs, but because it is very insoluble, the impact of pH is negligible unless captan is allowed to stand for a week or more. Hydrolysis increases with increased temperature. If the time in the spray tank is limited by applying pesticides immediately, then the quantitative amount broken down is limited.
Additives to the spray tank can also be a factor. Calcium chloride, especially when concentrated in the tank and applied in a low volume spray, can increase the pH. The greater the concentration, the greater the alkalinity. The manufacturing process for calcium chloride leaves residues of free lime (calcium hydroxide). The greater the purity of the calcium chloride, the lower the content of calcium hydroxide and the lower the effect on pH.
The water source can be a factor. Although most wells, streams, and rivers in the southeastern growing region are mildly acidic (6.7 plus or minus 0.2) there are exceptions; therefore, check pH a few times before regular use. Ponds are more likely to be alkaline, especially those high in algae and other organisms. These ponds undergo diurnal pH changes as result of dissolved carbon dioxide. Levels greater than 10 have been observed. Alkalinity contributed by CO2 is weakly buffered and readily changed by acidifying agents.
Although not pH-related, some pesticides can be affected by other contaminants in the water. For example, fenbuconazole, not labeled on apples, is greatly reduced in effectiveness by suspended particulates. Still other compounds like 2,4-D and azoxystrobilurin can be very difficult to wash out of the tank and can have a deleterious effect on apples at very low concentrations.
44
Orchard Floor Management
The best strategy for managing the orchard floor is to use a noncompetitive grass alley with a vegetation-free strip in the tree row. The vegetation-free strip can be established and maintained with herbicides as described in this section. The permanent grass sod between the tree rows will minimize soil erosion, increase soil aeration and permeability, and support equipment movement through the orchard during wet weather. The vegetation-free strip eliminates competition for water and nutrients, minimizes tree damage or loss from voles during the dormant season, and provides some radiant heat from the soil surface should a spring frost or freeze occur. Herbicides are directed at the soil and weeds underneath the tree.
The vegetation-free strip method is superior to all other orchard floor management options. Vegetation under the tree competes for nutrients and water, resulting in reduced growth, yield, and size of fruit. Another option is the use of organic mulches in the tree row. Examples of mulching materials include straw, wood chips, and grass residue from mowing. These mulches will suppress weed emergence, but weed removal by some means will still be necessary. Mulches can improve the water-holding capacity of some soils. However, there are several concerns regarding the use of organic mulches. The most significant problem is that mulches create an ideal habitat for voles. Also, additional nitrogen may be needed to support the microorganisms that drive decomposition of organic mulches. In poorly drained or waterlogged soils, organic mulches increase the likelihood of phytophthora root rot. Mulches can be expensive and difficult to obtain. Synthetic mulches made from polyethylene, polypropylene, or polyester can be placed in the tree row around the base of the trunk or as a narrow strip down the row. Some newer synthetics allow water and air to pass through the mulch.
Herbicide Considerations
To ensure proper herbicide use, always read the manufacturer’s label before application. All statements on the manufacturer’s label take precedence over any recommendations in this publication.
It is important that herbicide application equipment be properly calibrated to ensure that herbicides are applied at the correct rate. For questions about calibrating your sprayer, contact your county’s Cooperative Extension agent.
Remember that herbicides are applied as a directed spray along each side of the tree row. Flat fan nozzles are most widely used for applying herbicides. They provide excellent spray coverage of weeds and come in several sizes with capabilities to apply a range of spray volumes. Some manufacturers make flat fan nozzles that minimize spray drift, allowing low-pressure spraying. Investing in such spray nozzles decreases the likelihood of off-target herbicide movement.
It is advisable to apply white latex paint to the bottom 2 to 3 feet of the tree trunk of newly planted trees before applying herbicides. Painting the tree trunks reduces the potential for winter as well as herbicide injury, especially from postemergence herbicides. Dip a car wash mitt (wear rubber gloves underneath the mitt) in paint and rub up and down the tree trunk until it is completely painted.
Several herbicides are registered for use in apple orchards. Some are preemergence herbicides that control weeds that have not emerged, and others are postemergence herbicides that control emerged weeds. Preemergence herbicides

2016 Integrated Orchard Management Guide for Commercial Apples in the Southeast
Alabama Cooperative Extension System
Auburn University
University of Arkansas Division of Agriculture
Cooperative Extension Service
University of Arkansas
Clemson Cooperative Extension Service
Clemson University
University of Georgia Cooperative Extension Service
University of Georgia
North Carolina Cooperative Extension Service
North Carolina State University
University of Tennessee Agricultural Extension Service
University of Tennessee Poison Control Centers and Emergency Facilities
PESTICIDE POISONING Symptoms of pesticide poisoning may include headache, blurred vision, weakness, nausea, cramps, diarrhea, and chest discomfort. If any of these symptoms occur during or after mixing or applying pesticides or if an unintended unprotected exposure such as a spill occurs, stop work at once and take appropriate action. If pesticide is spilled on the skin, immediately wash the area thoroughly with large amounts of soap and water. If pesticide is in the eye, flush the eye for 15 minutes with running water. If pesticide is inhaled, move to open, clean air. If pesticide is ingested, rinse out the mouth. Follow all label first aid directions. Give CPR if indicated. Get help. Contact your physician or poison control center (listed below or on WPS safety poster). Transport the victim to the closest medical care facility. Take the pesticide container or the label with you, or have others search for the label and get it to the facility.
Most pesticide poisonings are due to overexposure to organophosphate and carbamate insecticides. Investigation indicates these are the result of misuse, disregard for safety precautions, and lack of proper hygiene during mixing and application. Ninety percent of occupational exposure is through the hands. Use neoprene or butyl rubber gloves. Rubber boots prevent acute exposure from spills and chronic exposure from accumulation of residues in materials of boots and shoes.
STATE-DESIGNATED POISON CENTERS
Dialing 1-800-222-1222 reaches the poison control center for the state from which the call is made.
ALABAMA
800-222-1222
Children’s of Alabama
1600 Seventh Avenue South
Birmingham, AL 35233
800-222-1222 (administration and emergency)
www.childrensal.org/rpcc
NORTH CAROLINA
800-222-1222
Carolinas Poison Center
PO Box 32861
Charlotte, NC 28232-2861
800-222-1222 (administration and emergency)
www.ncpoisoncenter.org
ARKANSAS
800-222-1222
Arkansas Poison & Drug Information Center
4301 West Markham, #522-2
Little Rock, AR 72205
501-686-6161 (administration)
www.uamshealth.com/poisoncontrol
SOUTH CAROLINA
800-222-1222
Palmetto Poison Center
University of South Carolina
Columbia, SC 29208
803-777-7909 (business)
www.poison.sc.edu
GEORGIA
800-222-1222
Georgia Poison Center Education Department
80 Jesse Hill Jr. Drive, SE
PO Box 26066
Atlanta, GA 30303
404-616-9237 (administration)
404-616-9000 (local)
404-616-9235 (education)
404-616-9287 (TDD)
www.georgiapoisoncenter.org
TENNESSEE
800-222-1222
Tennessee Poison Center
Suite 501
1313 21st Avenue South
Nashville, TN 37232
615-936-2047 (TTY)
615-936-0760 (administration) www.mc.vanderbilt.edu
(search “poison center”)
2016 Integrated Orchard Management Guide for Commercial Apples in the Southeast
Table of Contents
Pest and Orchard Management Program ....................................................... 2
Tree Row Volume: A Model for Determining Spray Volume ........................ 32
IPM Practices for Selected Pests ................................................................... 34
Pesticide Resistance Management ............................................................... 40
Effect of pH on Pesticide Activity .................................................................. 43
Orchard Floor Management.......................................................................... 44
Apple Pollination, Honey Bees, and Pesticides ............................................. 46
Soil and Plant Analysis Guidelines for Southeastern Apple Production ........ 46
Fertility Management Recommendations for Apples ................................... 48
Relative Effectiveness of Fungicides ............................................................. 49
Relative Effectiveness of Insecticides and Miticides ..................................... 53
Toxicity of Pesticides to Beneficial Arthropods ............................................. 54
Weed Response to Preemergence Herbicides .............................................. 56
Weed Response to Postemergence Herbicides ............................................ 57
Fungicides and Bactericides .......................................................................... 59
Insecticides and Miticides ............................................................................. 63
Herbicides ..................................................................................................... 68
Growth-Regulating Chemicals ....................................................................... 73
Vertebrate Management .............................................................................. 80
Pesticide Safety ............................................................................................. 86
EPA Registration Numbers of Various Materials ........................................... 87
Senior Editor: Jim Walgenbach, Extension Entomologist, N.C. State University
Section Editors:
Insect Management Jim Walgenbach
Cultural/Growth Regulators Mike Parker
Disease Management Sara Villani
Weed Management Wayne Mitchem
Vertebrate Management David Lockwood
Soils and Nutrition David Lockwood
Recommendations for the use of agricultural chemicals are included in this publication as a convenience to the reader. The use of brand names and any mention or listing of chemical products or services in this publication does not imply endorsement by the Cooperative Extension Service nor discrimination against similar products or services not mentioned. Individuals who use agricultural chemicals are responsible for ensuring that the intended use complies with current regulations and conforms to the product label. Be sure to obtain current information about usage regulations and examine a current product before applying any chemical. For assistance, contact your local Extension Agent. CONTRIBUTORS
Ed Sikora
Plant Pathology
Donn Johnson
Elena Garcia
Curt Rom
Entomology Horticulture
Horticulture
Mike Hood
Guido Schnabel Bob Bellinger
Apiculture
Plant Pathology Safety
Keith Delaplane
Dan Horton
Phillip Brannen
Harold Scherm Paul Gulliebeau
Apiculture
Entomology
Plant Pathology
Plant Pathology Safety
David Tarpy
Jim Walgenbach Wayne Mitchem
Mike Parker
Sara Villani
Apiculture
Entomology Horticulture
Horticulture
Plant Pathology
John Skinner
Frank Hale
David Lockwood Darrell Hensley
Apiculture
Entomology
Horticulture Safety
Pest and Orchard Management Program
DORMANT
Goals
Options
Relative1
Effectiveness (+)
or
Importance (*)
Amount per2
Re-entry
Interval
(hours)
Preharv.
Interval
(days)
Comments
100 gal
Acre
Cultural Management
Younger trees should be pruned closer to bud break. Prune older and bearing trees first; prune 1- to 2-year-old nonbearing trees during the month before dormant bud break.
Control canopy density, size, and shape for better light and spray penetration.
Conduct annual dormant pruning in central leader trees and appropriate high- density orchards.
*****
Provide proper nutrition for moderate tree growth and good fruit quality.
Collect soil samples; establish and maintain a good lime and fertility program. Apply late winter fertilizer to young, nonbearing trees, and half rate to mature, bearing trees.
*****
See Fertility Management section (page 48) for complete sampling, fertilizer rates, and application methods. Apply full rate to young, nonbearing trees to promote good tree growth.
Increase lateral bud break and lateral shoot development on last year’s leader growth to encourage scaffold limb development.
Bag last year’s leader growth 3 to 4 weeks before anticipated dormant bud break.
*****
See Growth-Regulating Chemicals section (page 73) for details.
Plant Growth Regulators
Control water sprout regrowth near pruning cuts and on tops of large scaffold limbs exposed to light by heavy dormant pruning.
Tre-Hold A-112
See comments.
Use 10,000 ppm (10 oz per gal) as a “sponge-on” application.
12
0
See Growth-Regulating Chemicals section (page 73) for complete recommendation details. The need for this practice depends on heaviness of pruning, size of cuts, and potential growth vigor. Effectiveness depends on COMPLETE coverage.
Control burr knot formation.
Gallex
**
Paint directly from can, full strength, on burr knots.
See Growth-Regulating Chemicals section (page 73) for recommendation details.
2 Goals
Options
Relative1
Effectiveness (+)
or
Importance (*)
Amount per2
Re-entry
Interval
(hours)
Preharv.
Interval
(days)
Comments
100 gal
Acre
Disease Management
May also help reduce inoculum of fungi that cause Brooks spot, Alternaria blotch, and Glomerella leaf spot.
Reduce inoculum of apple scab fungus.
Shred leaves with flail mower and/or apply urea to fallen leaves in autumn or spring prior to green tip.
*****
20 lb
Reduce inoculum of black, white, and bitter rot fungi.
Prune out dead wood and mummied fruit.
*****
Pruning is extremely important to reduce the likelihood of these diseases. Don’t stockpile prunings near orchard. Remove and burn, or chip with a flail mower.
Reduce inoculum of fire blight bacteria.
Prune out cankers and old fire blight strikes.
****
Will also reduce inoculum of black rot, white rot, and bitter rot.
Reduce inoculum of powdery mildew fungus.
Prune out silver-colored terminal shoots.
***
Particularly useful on young trees of a susceptible cultivar.
Improve control of cedar apple and quince rusts.
Scout orchard, adjacent woods, or borders for red cedar, and remove.
*****
Complete removal of red cedar in areas where cedars are not common may eliminate need for fungicide sprays for these diseases.
Improve conditions for drying fruit and foliage, spray penetration.
Prune to open trees.
*****
Pruning is extremely important for good disease control inside the canopy and in the tops of large trees.
Weed Management
Apply nonselective postemergence herbicide alone (mid-March). When control from this breaks and summer weeds are 2-3 inches tall, apply a nonselective postemergence herbicide with a preemergence herbicide. This will likely be in early May, but may vary from year to year. Delaying PRE herbicide application results in residual control later in the summer.
Control seedling perennials and winter annuals.
Apply glyphosate or glyphosate + 2,4-D amine or paraquat or Rely to control emerged winter annuals.
*****
+++++
See product label.
See product label.
Reduce dandelions.
2,4-D amine
++++
1 qt
1 lb
48
60
Apply at least 2 weeks before bloom to control flowering weeds. Reduces competition with apple blossoms to enhance bee pollination. Control of flowering weeds will also help control tarnished plant bug.
1Effectiveness ratings range from + = poor control to +++++ = excellent control. Importance ratings range from * = minor importance to ***** = very important.
2Rates expressed as amount per 100 gal for dilute and amount per acre are for concentrate applications based on a tree-row volume of 400 gal/acre.
3 SILVER TIP
Goals
Options
Relative1
Effectiveness (+)
or
Importance (*)
Amount per2
Re-entry
Interval
(hours)
Preharv.
Interval
(days)
Comments
100 gal
Acre
Disease Management
Control fire blight.
Bactericides
copper hydroxide
copper oxychloride sulfate Bordeaux
++++
++++
++++
See label.
See label.
See label.
See label.
See label.
See label.
This treatment will help control fire blight in blocks of trees of a susceptible cultivar where fire blight has been a problem. It will not eliminate need for streptomycin at bloom. Applications later than 0.25- to 0.5-inch green tip may result in fruit russet. Most effective if applied dilute.
Control black rot.
Fungicides
Captan 50W or
4L or
80W or
80WDG
++++
++++
++++
++++
—
—
4 lb
2 qt
2.5 lb
2.5 lb
24
24
24
24
0
0
0
0
An important spray for black rot control in Georgia. Warning: Captan will cause injury when used with or too close to oil applications.
Control crown rot
(collar rot).
Fungicides
Ridomil Gold SL
++++
See label.
48
N/A
Ridomil and Aliette applications are recommended on cultivars propagated on susceptible rootstocks planted in heavy or poorly drained soils. Apply Ridomil in the spring before growth starts, and repeat application after harvest. Apply 3 to 5 applications of Aliette a year. Make first application of Aliette after leaf emergence. Note: Ridomil and Aliette must be applied on a preventive basis. Treatment of trees exhibiting symptoms will not prevent further symptom development.
Aliette 80WDG
+++
2.5 to 5 lb
12
14
Phosphite fungicides
(i.e. Prophyt, Phostrol,
Agri-Fos)
++++
See label.
Phosphite fungicides are registered for crown rot control and have activity similar to Aliette. See labels for use instructions and precautions.
1Effectiveness ratings range from + = poor control to +++++ = excellent control. Importance ratings range from * = minor importance to ***** = very important.
2Rates expressed as amount per 100 gal for dilute and amount per acre are for concentrate applications based on a tree-row-volume of 400 gal/acre.
4 GREEN TIP TO ½-INCH GREEN
Goals
Options
Relative1
Effectiveness (+)
or
Importance (*)
Amount Per2
Re-entry
Interval
(hours)
Preharv.
Interval
(days)
Comments
100 gal
Acre
Disease Management
Control apple scab.
See discussion in Fungicides and Bactericides (page 59) for information on postinfection control program.
Fungicides
Syllit FL
+ mancozeb 75DF
or
+ Captan 80WDG
+++++
+++++
1.5 to 3 pt
3 lb
2.5 lb
48
24
24
7
77
0
Vangard 75WG
+++
5 oz
12
0
Vangard tends to be most active at cool temperatures.
Vangard 75WG
+ mancozeb 75DF
or
+ Polyram 80DF
++++
++++
3 to 5 oz
3 lb
3 lb
12
24
24
0
77
77
Scala SC
+++
7 to 10 oz
12
72
Scala SC is not compatible with Captan 50WP.
Scala SC
+ mancozeb 75DF
or
+ Polyram 80DF
++++
++++
5 oz
3 lb
3 lb
12
24
24
72
77
77
Captan 80WDG
++++
5 lb
24
0
Captec 4L
++++
0.75 to 1 qt
4 qt
24
0
Captan 50WP
++++
4 to 8 lb
24
0
Manzate ProStick
++++
3 to 6 lb
24
77, BL
Penncozeb 75DF
++++
3 to 6 lb
24
77, BL
Polyram 80DF
++++
3 to 6 lb
24
77, BL
Luna Tranquility
+ mancozeb 75DF
++++
+++++
11.2 to 16 fl oz
3 lb
12
24
72
77
1Effectiveness ratings range from + = poor control to +++++ = excellent control. Importance ratings range from * = minor importance to ***** = very important.
2Rates expressed as amount per 100 gal for dilute and amount per acre are for concentrate applications based on a tree-row-volume of 400 gal/acre.
5 GREEN TIP TO ½-INCH GREEN (continued)
Goals
Options
Relative1
Effectiveness (+)
or
Importance (*)
Amount Per2
Re-entry
Interval
(hours)
Preharv.
Interval
(days)
Comments
100 gal
Acre
Control scab (continued).
Fontelis SC
+++++
16 to 20 fl oz
12
28
Fontelis SC
+ mancozeb 75DF
+++++
+++++
16 to 20 fl oz
3 lb
12
24
28
77
Control fire blight.
Badge SC
++++
+++
3.5 to 7 pt
0.5 to 1.5 pt
48
See label.
Apply this rate between silver and green tip only.
Extended spray schedule; may harm fruit.
Badge X2
++++
+++
3.5 to 7 lb
0.5 to 1.5 lb
48
See label.
Apply this rate between silver and green tip only.
Extended spray schedule; may harm fruit.
Kocide 3000
++++
3.5 to 7 lb
48
See label.
Make application between silver and green tip; discontinue use at this rate at ½” green.
Cuprofix Ultra Disperss 40DF
++++
5 to 7.5 lb
48
See label.
Apply this rate between silver and green tip only.
Champ Formula 2F
++++
5.3 to 10.5 pt
48
See label.
Apply this rate between silver and green tip only.
Control Phytophthora rots.
Phostrol
+++++
0.6 pt
2 to 5 pt
4
0
Prophyt
+++++
2 to 4 pt
4
0
1Effectiveness ratings range from + = poor control to +++++ = excellent control. Importance ratings range from * = minor importance to ***** = very important.
2Rates expressed as amount per 100 gal for dilute and amount per acre are for concentrate applications based on a tree-row-volume of 400 gal/acre.
6 GREEN TIP TO ½-INCH GREEN (continued)
Goals
Options
Relative1 Effectiveness (+)
or
Importance (*)
Amount Per2
Re-entry Interval (hours)
Preharv. Interval (days)
Comments
100 gal
Acre
Insect Management
Use either a superior-type or highly refined summer oil applied dilute. If the oil application is delayed until tight cluster to pink, use a refined oil or reduce a superior type to ½ to 1 gal/100 gal. Do not use captan within 2 weeks of an oil application.
Control scales and reduce overwintering European red mite and rosy apple aphid eggs.
Insecticides
Oil
+++++
2 gal
2 to 3% solution
12
0
Improve scale control.
Oil +
Lorsban 4E
or
Esteem 35WP
or
Centaur 70WDG
++++
+++++
+++++
2 gal
½ to 1 pt
—
—
8 gal
2 to 4 pt
4 to 5 oz
9 to 12 oz
12
96
12
12
0
DD
45
14
An insecticide with oil may be added at this time in orchards experiencing problems with scales. This option is recommended in orchards that experienced scale problems the previous year. The window of control with Esteem or Centaur can be extended to first cover. NOTE: if using Esteem or Centaur, application can be made anytime between green tip and 1st Cover.
Initiate oriental fruit moth (OFM) monitoring program.
Erect pheromone traps.
*****
Erect pheromone traps by green tip to detect first emergence. See section on IPM Practices for Selected Pests (page 34) for monitoring information.
Mating disruption for OFM and codling moth.
Pheromones
Isomate CM/OFM TT
CheckMate Puffer - CM/OFM
+++++
++++
(number of dispensers)
200/acre
1/acre
Now is the time to begin erecting pheromone dispensers for mating disruption. Combination dispensers that contain both OFM and codling moth pheromone are recommended. Hanging of dispensers in trees should be complete by the end of bloom. See section on “Mating Disruption” in IPM Practices for Selected Pests (page 37).
1Effectiveness ratings range from + = poor control to +++++ = excellent control. Importance ratings range from * = minor importance to ***** = very important.
2Rates expressed as amount per 100 gal for dilute and amount per acre are for concentrate applications based on a tree-row-volume of 400 gal/acre.
7
7 TIGHT CLUSTER TO PINK
Goals
Options
Relative1
Effectiveness (+)
or
Importance (*)
Amount per2
Re-entry
Interval
(hours)
Preharv.
Interval
(days)
Comments
100 gal
Acre
Disease Management
Control apple scab.
Fungicides
Captan 80WDG
Captan 50WP
Captec 4L
Manzate ProStick
Penncozeb 75DF
Polyram 80DF
Flint WG
Sovran WG
Indar 2F
Luna Tranquility
Luna Sensation
Merivon
Fontelis
Inspire Super
Aprovia
++++
++++
++++
++++
++++
++++
+++++
+++++
+++++
++++
+++++
+++++
+++++
+++++
+++++
0.75 to 1 qt
5 lb
4 to 8 lb
4 qt
3 to 6 lb
3 to 6 lb
3 to 6 lb
2 to 2.5 oz
3.2 to 6.4 oz
6 to 8 fl oz
11.2 to 16 fl oz
4 to 5.8 fl oz
4 to 5.5 fl oz
16 to 20 fl oz
12 fl oz
5.5 to 7 fl oz
24
24
24
24
24
24
12
12
12
12
12
12
12
12
12
0
0
0
77, BL
77, BL
77, BL
14
30
14
72
14
0
28
14
30
Combine Flint WG with a half rate of mancozeb or captan for resistance management.
For resistance management combine Fontelis with half rate of mancozeb. See label for Fontelis rates when applied with mancozeb.
Control powdery mildew.
Fungicides
Rally 40WSP
Procure 50WS
Indar 2F
Topguard 1.04SC
Luna Sensation 500SC
Luna Tranquility 4.16SC
Merivon 4.18SC
Fontelis 1.67SC
Flint 50WG
Sovran 50WDG
Aprovia
JMS Stylet Oil
Microthiol Disperss
+++++
++++
++++
+++++
+++++
++++
+++++
+++
++++
+++++
++++
+++
++++
1 to 2 gal
5 to 10 oz
4 to 8 oz
8 fl oz
8 to 12 fl oz
4 to 5.8 fl oz
11.2 to 16 fl oz
4 to 5.5 fl oz
14 to 20 fl oz
2 to 2.5 oz
4 to 6.4
5.5 to 7 fl oz
10 to 20 lb
24
12
12
12
12
12
12
24
12
12
12
4
24
14
14
14
14
14
72
0
28
14
30
30
0
See label.
Tight cluster to petal fall are the most important sprays for the control of powdery mildew.
Do not use EC or solvent-based products, crop oil concentrate, or methylated seed oil adjuvants with Merivon.
Applying Stylet Oil with or following an application of captan will cause severe phytotoxicity.
1Effectiveness ratings range from + = poor control to +++++ = excellent control. Importance ratings range from * = minor importance to ***** = very important.
2Rates expressed as amount per 100 gal for dilute and amount per acre are for concentrate applications based on a tree-row volume of 400 gal/acre.
8 TIGHT CLUSTER TO PINK (continued)
Goals
Options
Relative1
Effectiveness (+)
or
Importance (*)
Amount per2
Re-entry
Interval
(hours)
Preharv
Interval
(days)
Comments
100 gal
Acre
Control cedar apple rust and quince rust.
Fungicides
Use a DMI (FRAC 3) fungicide used for powdery mildew or apple scab, or:
mancozeb 75DF
++++
3 lb
24
77
DMI fungicides have after-infection activity on rusts.
Mancozeb and Polyram do not control powdery mildew.
Control black rot and frogeye leafspot.
Captan 50WP
Captan 4L
Captan 80WDG
Thiophanate Methyl 85WDG
Topsin 4.5FL
Topsin M WSB
++++
++++
++++
+++++
+++++
+++++
0.5 to 1 qt
0.2 to 0.3 lb
3.8 to 5 fl oz
0.2 to ¼ lb
4 to 8 lb
3 to 4 qt 2.5 to 5 lb
0.6 to 0.8 lb
15 to 20 fl oz
¾ to 1 lb
24
24
24
48
48
48
0
0
0
1
1
1
Captan does not control powdery mildew or rust diseases.
Many populations of apple scab are resistant to T-Methyl and Topsin fungicides.
Insect Management
Erect traps now because moths begin to emerge near bloom. See section on IPM Practices for Selected Pests (page 34) for information on monitoring programs.
Initiate codling moth and leafroller monitoring program.
Erect pheromone traps.
*****
Control rosy apple aphid.
Insecticides
Actara 25WDG
Assail 30SG
Calypso 4F
Belay SC
Sivanto 200SL
Asana XL
Danitol 2.4EC
Permethrin 3.2EC
+++++
+++++
+++++
+++++
++++
++++
++++
++++
—
—
—
—
—
2 to 5.8 fl oz
2.6 to 4.3 oz
—
4.5 oz
2.5 to 4 oz
2 to 4 oz
6 fl oz
7 to 10 oz
4.8-14.5 fl oz
10.6-21.3 oz
4 to 10 fl oz
12
12
12
12
4
12
24
12
35
7
30
21
14
7
14
*
Pink stage is the best time to control rosy apple aphid. Caution: Rosy apple aphid resistance to pyrethroids has been observed in some orchards. See Rosy Apple Aphid resistance section (page 41). Pyrethroids can lead to flare-ups of mites, scales, and woolly apple aphids.
*Do not apply Permethrin after petal fall.
1Effectiveness ratings range from + = poor control to +++++ = excellent control. Importance ratings range from * = minor importance to ***** = very important.
2Rates expressed as amount per 100 gal for dilute and amount per acre are for concentrate applications based on a tree-row volume of 400 gal/acre.
9 TIGHT CLUSTER TO PINK (continued)
Goals
Options
Relative1
Effectiveness (+)
or
Importance (*)
Amount per2
Re-entry
Interval
(hours)
Preharv
Interval
(days)
Comments
100 gal
Acre
Control plant bugs
and spotted tentiform leafminer (STLM).
Maintain clean ground-cover. Insecticides listed for rosy apple aphid will aid in plant bug and leafminer control if plant bugs are readily seen.
*****
In many instances, a clean groundcover eliminates the need for insecticides to control bugs. If there is a history of plant bug problems, a second application at petal fall will improve control. Insecticides specifically targeting STLM are rarely needed because biological control agents are highly effective.
1Effectiveness ratings range from + = poor control to +++++ = excellent control. Importance ratings range from * = minor importance to ***** = very important.
2Rates expressed as amount per 100 gal for dilute and amount per acre are for concentrate applications based on a tree-row volume of 400 gal/acre.
10 BLOOM
Goals
Options
Relative1
Effectiveness (+)
or
Importance (*)
Amount per2
Re-entry
Interval
(hours)
Preharv.
Interval
(days)
Comments
100 gal
Acre
Cultural Management
Loosen bags on leaders to acclimate for 2 to 3 days; then remove bags from leaders and spray with Promalin or Perlan.
Leader bags must be removed when new lateral growth is 1 to 3 inches long.
*****
See Growth-Regulating Chemicals section (page 73) for complete details.
Do leader selection and strip whorl on dormant headed tree leaders.
Select new shoot for central leader and remove competing shoots from first four nodes below new leader shoot.
Plant Growth Regulators
See Growth-Regulating Chemicals section (page 73). Apply as a fine mist application at 40 to 50% of Tree Row Volume (TRV) water rate between early king bloom and early petal fall of the side blossoms. Split applications during this period can be more effective.
Improve fruit shape and increase fruit weight of Red and Golden Delicious and Gala.
(BA+GA 4 + 7)
Promalin
Perlan
+++
+++
0.5 to 1 pt
1 to 2 pt
4
4
None
Increase lateral bud break and lateral shoot growth on 1-year-old leader growth as a tool to encourage scaffold limb development, especially on those that were bagged before bud break. Use on nonbearing trees only.
Promalin
Perlan
+++++
+++++
125 to 500 ppm
(0.5 to 2 pt)/
10 gal
125 to 500 ppm
(0.5 to 2 pt)/
10 gal
4
4
None
Apply to last year’s leader growth at 1-3 inches of new terminal growth with a handheld nozzle. See Growth-Regulating Chemicals section (page 73).
Make one application when orchard trees have 1 to 3 inches of new growth or when the leader has reached the height where branching is required.
1Effectiveness ratings range from + = poor control to +++++ = excellent control. Importance ratings range from * = minor importance to ***** = very important.
2Rates expressed as amount per 100 gal for dilute and amount per acre are for concentrate applications based on a tree-row-volume of 400 gal/acre.
11 BLOOM (continued)
Goals
Options
Relative1
Effectiveness (+)
or
Importance (*)
Amount per2
Re-entry
Interval
(hours)
Preharv.
Interval
(days)
Comments
100 gal
Acre
To increase fruit set after a frost.
Promalin
Perlan
++
++
16-32 fl. oz
16-32 fl. oz
Apply within 24 hours after a frost that occurs when most of the crop is between early bloom and full bloom. Apply in 75 to 150 gallons of water per acre. Do not apply to frozen foliage, blossoms, or developing fruit. Allow trees to completely thaw prior to application. Do not use a surfactant.
Disease Management
Control apple scab, rusts, powdery mildew, and black rot.
Fungicides
Same fungicides as for tight cluster.
Avoid sprays in full bloom if possible. Do not overextend application intervals.
Control fire blight.
Bactericides
Streptomycin
(i.e. Agri-mycin, Firewall, Streptrol)
Kasumin 2L
Mycoshield 17WP
Fireline
Actigard
+ streptomycin
or
+ oxytetracyline
Bloomtime Biological
Cueva
Double Nickel LC
+ Cueva
Serenade Optimum
MasterCop
Badge SC
Badge X2
+++++
+++++
++++
++++
+++++
++++
++
+++
+++
++
+++
+++
+++
64 fl oz
1 lb
12 oz
0.125 to 0.8 oz
0.75 to 1 lb
24 oz
-
-
-
0.5 to 3.2 oz
24 oz
0.33 lb
2 to 3 qt
1 to 2 qt
2 to 3 qt
14 to 20 oz
0.5 to 1.5 qt
0.5 to 1.5 pt
0.5 to 1.5 lb
12
12
12
12
12
4
4
4
4
48
48
48
50
90
60
60
60
See label.
0
0
0
See label.
See label.
See label.
Begin application at first bloom and continue at 3- to 4-day intervals until petal fall. It is very important to continue spraying through late “rat-tail” bloom, especially on susceptible varieties. See discussion under Pesticide Resistance Management section (page 40) for timing sprays according to conditions favorable for infection.
Bloomtime Biological is not compatible with coppers. Approved for organic production.
Cueva may result in phytotoxicity to fruit and leaves. If concerned, use lower rate. OMRI approved.
Serenade Optimum is approved for organic production.
Badge X2 is OMRI approved.
Insect Management
Keep orchard floor free of flowering weeds. This will increase pollination in the trees and lessen bee activity after apple bloom.
Protect pollinators.
12 PETAL FALL
Goals
Options
Relative1
Effectiveness (+)
or
Importance (*)
Amount per2
Re-entry
Interval
(hours)
Preharv.
Interval
(days)
Comments
100 gal
Acre
Cultural Management
If boron is low in leaf sample or cork spot has been a problem in past years, a second and third application may be used. Dilute applications are necessary for good uptake. See Fertility Management section (page 48).
Reduce fruit corking.
Solubor
or
Borosol
+++
+++
1 lb
at first cover
1 pt
Reduce fruit corking and bitter pit.
calcium chloride
+++
2 lb
beginning at first cover
Repeat calcium sprays in each cover spray all season. Do not apply calcium chloride when temperatures are above 85°F, and DO NOT tank mix with Solubor or Apogee. All calcium sprays should be applied dilute for maximum response, especially for bitter pit control in late season cover sprays when fruit are becoming waxy. See Fertility Management section (page 48).
Plant Growth Regulators
Reduce fruit russeting on susceptible cultivars (esp. Golden Delicious).
(GA4+7)
ProVide 10SG
Novagib 10L
++++
++++
2.1 to 3.5 oz
(60 to 100 g)
20 to 33 fl. oz
4
4
None
At petal fall, begin the first of 2 to 4 applications at 7- to 10-day intervals. See Growth-Regulating Chemicals section (page 73) for complete recommendations.
Thin fruit to reduce crop load and encourage return bloom.
Depends on cultivar, fruit size, and thinning chemical. Applications from petal fall to about 8 mm would be applied during this time.
+++++
See thinning chart on page 76.
Check label for specific thinning chemical(s) to be used.
See Chemical Fruit Thinning Spray and Apple Thinning recommendations chart in Growth-Regulating Chemicals section.
Initiate vegetative growth control applications.
Suppress shoot blight.
Prohexadione Calcium
(Apogee or Kudos)
++++
Use at TRV calculated a.i./acre.
9 to 24 fl. oz
12
45
See prohexadione calcium table in Growth-Regulating Chemicals section (page 78).
1Effectiveness ratings range from + = poor control to +++++ = excellent control. Importance ratings range from * = minor importance to ***** = very important.
2Rates expressed as amount per 100 gal for dilute and amount per acre are for concentrate applications based on a tree-row-volume of 400 gal/acre.
13 PETAL FALL (continued)
Goals
Options
Relative1
Effectiveness (+)
or
Importance (*)
Amount per2
Re-entry
Interval
(hours)
Preharv.
Interval
(days)
Comments
100 gal
Acre
Disease Management
Control apple scab.
Fungicides
Same fungicides as recommended for tight cluster/pink and bloom stages.
Plant tissue during early shoot growth can be very sensitive to injury by captan. Be careful with tank mixtures containing captan and adjuvants.
Control black rot and white rot.
Fungicides
Captan 50 WP
Captec 4L
Captan 80WDG
Sovran 50WG
Flint 50WG
Thiophanate Methyl 85WDG
Topsin 4.5FL
Topsin M WSB
++++
++++
++++
++++
+++++
+++++
+++++
+++++
1 qt
0.2 to 0.3 lb
3.75 to 5 fl oz
0.2 to 0.25 lb
8 lb
4 qt
5 lb
4 to 6.4 oz
1.5 to 2.5 oz
0.6 to 0.8 lb
15 to 20 fl oz
¾ to 1 lb
24
24
24
12
12
48
48
48
0
0
0
30
14
1
1
1
Control Colletotrichum pathogens: Glomerella leaf spot/Bitter rot.
Fungicides
Captan 50 WP
Captec 4L
Captan 80WDG
Ziram 76 DF
++++
++++
++++
++++
1 qt
8 lb
4 qt
5 lb
6 lb
24
24
24
48
0
0
0
14
Mancozeb is not specifically labeled for Colletotrichum pathogens in apple. If applying mancozeb for control of apple scab, use a half rate of captan and a half rate of mancozeb.
ProPhyt
+ Captan 80 WDG
or
+ Ziram 76 DF
+++++
1.5 lb
4 pt
3.75 lb
6 lb
4
24
48
0
0
14
ProPhyt can also be applied in tank mixture with mancozeb (3 lb rate) if mancozeb is applied for protection against apple scab and cedar apple rust.
Sovran 50WG
++++
4 to 6.4 oz
12
30
Sovran and Flint will also control apple scab and powdery mildew.
Flint 50WG
+++++
2.5 to 3 oz
12
14
Pristine 38W
+++++
14.5 to 18 oz
12
0
Merivon 4.18SC
+++++
4 to 5.5 fl oz
12
0
Omega 500F
++++
13.8 fl oz
12
28
14 Goals
Options
Relative1
Effectiveness (+)
or
Importance (*)
Amount per2
Re-entry
Interval
(hours)
Preharv.
Interval
(days)
Comments
100 gal
Acre
Control Brooks fruit spot.
Fungicides
Use protectant fungicides (captan, mancozeb, Ziram) or benzimidazole fungicides (i.e. benzimidazoles) listed above for summer rots.
*****
Petal fall through third cover sprays are the most important sprays for Brooks spot control. Generally, the EBI and QoI fungicides may have limited Brooks spot activity. If one of them is used, combine it with a full rate of protectant.
Control powdery mildew and cedar apple rust.
Fungicides
See tight cluster to pink spray.
If captan alone is used in this application, fungicides with strong activity on powdery mildew and cedar apple rust should be included in this application.
Insect Management
*When choosing an insecticide at petal fall or any other time, choose one that provides control of the spectrum of insects present at the time of application.
Preventive control of mites is not recommended unless insecticides known to flare mites are anticipated to be used.
An application of Agri-Mek at petal fall to first cover should provide season-long suppression of these pests. A paraffinic spray oil (0.25% or 1 gal/acre) must be tank mixed to ensure Agri-Mek’s activity. Do not use captan 2 weeks before or after applying oil with Agri-Mek.
Preventively control European red mite, spotted tentiform leafminer, and white apple leafhopper.
Insecticides
Agri-Mek 0.15EC
+
oil
+++++
2.5 oz
10 oz
12
28
Preventive control of European red mite.
Apollo SC
Savey 50WP
Zeal 72WDG
Envidor 2SC
++++
++++
+++++
+++++
—
—
—
—
4 oz
3 oz
2 to 3 oz
16 to 18 oz
12
12
12
12
45
28
28
7
Apply one of these products between petal fall and third cover or when mites reach one adult per leaf. See page 41 for resistance management of European red mite.
1Effectiveness ratings range from + = poor control to +++++ = excellent control. Importance ratings range from * = minor importance to ***** = very important.
2Rates expressed as amount per 100 gal for dilute and amount per acre are for concentrate applications based on a tree-row-volume of 400 gal/acre.
15 PETAL FALL (continued)
Goals
Options
Relative1
Effectiveness (+)
or
Importance (*)
Amount per2
Re-entry
Interval
(hours)
Preharv.
Interval
(days)
Comments
100 gal
Acre
Control plum curculio.
Insecticides
Avaunt 30WG
Actara 25SDG
Imidan 70WP
Belay SC
Sevin 50WP
+++++
+++++
++++
++++
+++
—
—
¾ lb
—
½ lb
5 to 6 oz
4.5 oz
3 lb
6 oz
1 lb
12
12
24
12
12
28
35
7
7
3
Adults begin to enter orchards during bloom, with most, but not all, adults present by late petal fall. An insecticide applied at petal fall is important to minimize damage. Cool weather during this period, or historically large populations, may extend adult activity, which may require a second application 10 days later.
Control oriental fruit moth.
Insecticides
Imidan 70WP
Avaunt 30WG
Sevin 50WP
Assail 30SG
Mating Disruption
Isomate OFM-TT
CheckMate OFM-F
+++++
+++++
+++
+++++
+++++
+++++
¾ lb
—
½ lb
—
3 lb
5 to 6 oz
2 lb
5 to 8 oz
50-100 disp.
1 to 2 fl oz
24
12
12
12
0
0
7
28
3
7
0
0
An insecticide applied between 500 and 600 degree days (DD) after biofix will control the first generation. First generation OFM is controlled with a single application of an insecticide at petal fall.
In those orchards not using mating disruption (e.g., Isomate TT or Puffers), CheckMate OFM-F, a sprayable formulation, should be considered in early to mid August for control of late-season OFM. A second application in early September may be necessary for later-maturing varieties.
Control San Jose scale.
Insecticides
Diazinon 50WP
Esteem 0.86EC
Centaur 70WP
Movento 2SC
Assail 30SG
summer oil
+++++
+++++
+++++
+++++
+++
+++
1 lb
—
—
—
—
—
4 lb
4 oz
34.5 oz
6 to 9 oz
8 oz
1 to 2%
96
12
12
24
12
12
21
45
14
7
7
0
Where scales have been a problem the previous year, apply an insecticide for first generation crawlers, which are active from petal fall through third cover. Yellow crawlers can be detected by wrapping double-stick tape around infested limbs after bloom and inspecting weekly. Caution: Diazinon or oil applied with captan or Captec may cause phytotoxicity.
Control rosy apple aphid.
Insecticides
Admire 4.6SC
Actara 25WP
Assail 30SG
Sivanto 200SL
Movento 2SC
+++++
+++++
+++++
+++++
++++
—
—
—
—
—
2.8 oz
4.5 oz
2.5 to 4.0 oz
7 to 10 oz
6 to 9 oz
12
12
12
4
24
7
35
7
14
7
If an insecticide was not applied for rosy apple aphid at pink, or if control was poor, an insecticide should be applied. An adjuvant must be applied with Movento.
See Rosy Apple Aphid resistance section (page 41).
16 Goals
Options
Relative1
Effectiveness (+)
or
Importance (*)
Amount per2
Re-entry
Interval
(hours)
Preharv.
Interval
(days)
Comments
100 gal
Acre
Control white apple leafhopper.
Insecticides
Sevin 50WP
Actara 25WDG
Admire 4.6SC
Assail 30SG
Avaunt 30WG
Sivanto 200SL
+++++
+++++
+++++
+++++
+++++
+++++
½ lb
—
—
—
—
—
2 lb
2 to 2¾ oz
2.8 oz
2.5 to 4 oz
5 to 6 oz
7 to 10 oz
12
12
12
12
12
4
1
35
7
7
28
14
Threshold level for first generation white apple leafhopper is 1 nymph per leaf. Thinning apples with Sevin during this time controls leafhoppers. Leafhoppers may be present from petal fall to second cover spray.
Control spotted tentiform leafminer.
Insecticides
Actara 25WDG
Delegate WG
Provado 1.6F
Assail 30SG
++++
+++++
++++
++++
—
—
1 to 2 oz
—
4.5 oz
4.5 oz
4 to 8 oz
1.1 oz
12
4
12
12
35
7
7
7
Threshold level for first generation leafminer is one mine per leaf. The need for leafminer control is rare, as biological control is highly effective.
Control green fruitworm.
Insecticides
Intrepid 2F
+++++
—
6 to 8 fl oz
4
14
Scout trees for feeding damage on shoots and new apples. An application of Intrepid at early petal fall will help to minimize damage to fruit. Intrepid is highly safe to bees and can be sprayed during bloom.
Weed Management
Control weeds.
Check orchards for weed populations.
*****
Identify weed problems so herbicide program can be adjusted for summer weed control.
Apply PRE + Nonselective POST herbicide.
See herbicide guide.
*****
See product labels.
See product labels.
Apply when summer weeds are 2 to 3 inches tall. Delaying application of preemergence herbicides until early May extends summer weed control.
Suppress clover bloom to protect bees from insecticide sprays.
2,4-D
*****
1 qt
48
60
Apply 2,4-D 7 to 10 days before spraying insecticides to suppress clover and avoid killing bees.
1Effectiveness ratings range from + = poor control to +++++ = excellent control. Importance ratings range from * = minor importance to ***** = very important.
2Rates expressed as amount per 100 gal for dilute and amount per acre are for concentrate applications based on a tree-row-volume of 400 gal/acre.
17 FIRST COVER
Goals
Options
Relative1
Effectiveness (+)
or
Importance (*)
Amount per2
Re-entry
Interval
(hours)
Preharv.
Interval
(days)
Comments
100 gal
Acre
Disease Management
If primary apple scab is controlled early, continue to protect with captan. Products used for summer disease control, with the exception of benzimidazoles (due to resistance concerns) should also generally be effective against apple scab. DMI fungicides will provide post-infection activity as well.
Control apple scab.
Fungicides
Scout for secondary apple scab. See comments.
*****
Control blister spot.
Fungicides
Aliette WDG
Phostrol
++++
++++
0.5 to 1 gal
2.5 to 5 pt
12
4
14
0
Fruit are most susceptible to blister spot 2 to 8 weeks following petal fall.
Control flyspeck/sooty blotch.
Fungicides
Captan 50WP
Captec 4L
Captan 80WDG
Sovran 50WG
Flint 50WG
Thiophanate Methyl 85WDG
Topsin 4.5FL
Topsin M WSB
Ziram 76 DF
Inspire Super
Indar 2F
Aprovia
Luna Sensation
Merivon
Pristine 38WDG
Cueva
Double Nickel LC
+ Cueva
++++
++++
++++
++++
+++++
+++++
+++++
+++++
++++
+++++
++++
+++++
+++++
+++++
+++++
+++
+++
0.5 to 1 qt
1 to 1.6 oz
0.15 to 0.2 lb
3.75 to 5 fl oz
0.2 to 0.25 lb
4 to 8 lb
2 to 4 qt
2.5 to 5 lb
4 to 6.4 oz
1.5 to 2.5 oz
0.6 to 0.8 lb
15 to 20 fl oz
¾ to 1 lb
6 lb
12 fl oz
6 to 8 fl oz
5.5 to 7 fl oz
4 to 5.8 fl oz
4 to 5.5 fl oz
14.5 to 18.5 oz
2 to 3 qt
1 to 2 qt
2 to 3 qt
24
24
24
12
12
48
48
48
48
12
12
12
12
12
12
4
4
0
0
0
30
14
1
1
1
12
14
14
30
14
0
0
0
0
For resistance management, it is recommended that single site fungicides be applied in tank mixture with a protectant fungicide such as captan.
Cueva may result in phytotoxicity to some apple cultivars.
1Effectiveness ratings range from + = poor control to +++++ = excellent control. Importance ratings range from * = minor importance to ***** = very important.
2Rates expressed as amount per 100 gal for dilute and amount per acre are for concentrate applications based on a tree-row-volume of 400 gal/acre.
18 Goals
Options
Relative1
Effectiveness (+)
or
Importance (*)
Amount per2
Re-entry
Interval
(hours)
Preharv.
Interval
(days)
Comments
100 gal
Acre
Control fire blight.
Apogee
Firewall 17WP
or other strepto-mycin products
Cueva
or other low MCE product
+++++
+++++
+++
4.5 to 9 fl oz
24 oz
2 qt
12
12
4
45
50
0
Apply Apogee when shoots are 1 to 3 inches long and 14 to 21 days after initial application.
Application of streptomycin regularly during summer cover applications is believed to hasten development of resistance.
Cueva may cause phytotoxicity, particularly on sensitive cultivars.
Control Alternaria leaf blotch, black rot, white rot.
Refer to fungicides used for Petal Fall application.
Control Colletotrichum pathogens: Glomerella leaf spot/Bitter rot.
Refer to fungicides used for Petal Fall application.
Control powdery mildew.
Refer to fungicides used for Petal Fall application.
1Effectiveness ratings range from + = poor control to +++++ = excellent control. Importance ratings range from * = minor importance to ***** = very important.
2Rates expressed as amount per 100 gal for dilute and amount per acre are for concentrate applications based on a tree-row-volume of 400 gal/acre.
19 FIRST COVER (continued)
Goals
Options
Relative1
Effectiveness (+)
or
Importance (*)
Amount per2
Re-entry
Interval
(hours)
Preharv.
Interval
(days)
Comments
100 gal
Acre
Insect Management
Control codling moth.
Monitor codling moth adult activity.
Insecticides
Delegate 25WP
Altacor 35WDG
Exirel 0.83SE
Voliam Flexi
Belt 4SC
Intrepid 2F
Rimon 0.83EC
Imidan 50WP
Assail 30SG
CYD-X
*****
+++++
+++++
+++++
+++++
++++
++++
++++
++++
+++
++++
—
—
—
—
—
—
—
¾ lb
—
—
4.5 to 7 oz
2.5 to 4.5 oz
8.5 to 17 oz
4 to 7 oz
3 to 5 fl oz
10 to 16 oz
20 to 40 oz
3 lb
4 to 8 oz
1 to 3 oz
4
4
12
12
12
4
12
24
12
4
7
5
3
35
14
14
14
7
7
0
See IPM Practices for codling moth (page 34) to determine how to minimize insecticide applications for codling moth control.
Voliam Flexi (which is a mixture) is recommended only at first cover when late emerging plum curculio is a concern, and a minimum of 6.0 oz should be used.
CYD-X is a virus that controls only codling moth. Frequent applications (7 to 10 days) at low rates (1 to 2 oz per acre) have worked well in field trials.
Codling moth insecticide-resistant populations exist in some orchards and can affect the performance of certain products.
Control rosy apple aphid, plum curculio, white apple leafhopper, spotted tentiform leafminer, and San Jose scale.
Monitor orchards for these insects.
Insecticides
(See Petal Fall section,
page 13)
*****
Infestations of these insects may occur anytime from petal fall to the second cover spray. Early detection is important for effective control.
1Effectiveness ratings range from + = poor control to +++++ = excellent control. Importance ratings range from * = minor importance to ***** = very important.
2Rates expressed as amount per 100 gal for dilute and amount per acre are for concentrate applications based on a tree-row-volume of 400 gal/acre.
19
20 SECOND COVER AND LATER SPRAYS
Goals
Options
Relative1
Effectiveness (+)
or
Importance (*)
Amount per2
Re-entry
Interval
(hours)
Preharv.
Interval
(days)
Comments
100 gal
Acre
Cultural Management
See information listed in Petal Fall to First Cover sections (pages 13 through 17) and Fertility Management section (page 48).
Reduce fruit corking and bitter pit.
calcium nitrate
calcium chloride
+++
+++
3 lb
2 lb
Provide proper nutrition for moderate tree growth and good fruit quality.
Apply second half of fertilizer to mature, bearing trees if crop load is present, as soon as frost/freeze danger is past (approximately second cover).
++++
See Fertility Management Recommendations section (page 48) for fertilizer use suggestions and complete recommendations.
Collect leaf samples in July to mid-August for leaf analysis.
+++++
See Fertility Management Recommendations section (page 48) for complete details.
Achieve proper tree training, and control tree size and density for good light and spray penetration.
Select lateral limbs, strip whorls, establish wide crotch angles with toothpicks or clothespins, and prop limbs to good limb angles (60-90° for central leader trees and 75-85° below vertical for high density, slender, spindle-type trees).
++++
Tree training is mandatory to develop proper lateral branching and limb position.
Do detailed young tree management (deshoot, position limbs, tie up leader) every 6 to 8 weeks until full tree size and bearing are achieved (especially for high density orchards).
++++
Summer pruning is a necessary extension of tree training begun earlier. Summer pruning helps contain tree size and density, and proper limb selection and positioning encourage flower initiation.
Remove water sprouts.
++++
Removing upright water sprout growth reduces canopy density, allowing greater spray penetration and better light distribution for fruit quality and color development. Summer pruning and removal of water sprouts also help control sooty blotch and flyspeck.
Do leader manipulation, such as summer bending or snaking, every 18 inches of terminal growth extension.
++
1Effectiveness ratings range from + = poor control to +++++ = excellent control. Importance ratings range from * = minor importance to ***** = very important.
2Rates expressed as amount per 100 gal for dilute and amount per acre are for concentrate applications based on a tree-row volume of 400 gal/acre.
21 SECOND COVER AND LATER SPRAYS (continued)
Goals
Options
Relative1
Effectiveness(+)
or
Importance (*)
Amount per2
Re-entry
Interval
(hours)
Preharv.
Interval
(days)
Comments
100 gal
Acre
Plant Growth Regulators
Thin to reduce crop load and encourage return bloom.
Depends on cultivar, fruit size, and thinning chemical selected. Application time from approximately 9 mm and larger would be applied from second cover on.
+++++
See thinning chart on page 76.
See Chemical Fruit Thinning Sprays (page 73) and Apple Thinning Recommendations chart (page 76) in Growth-Regulating Chemicals section.
Enhance return bloom.
Fruitone L or PoMaxa
Ethrel
+++
+++
2-8 fl. oz
16 to 72
fl. oz
48
48
2
7
Studies in the Southeast have found that NAA or Ethrel treatments can improve return bloom. Ethrel rate depends on many factors, including cultivar and crop load. Refer to table on page 75.
Control ground suckers around base of trunk.
Tre-Hold A-112 Sprout Inhibitor. Also use herbicides approved for sucker control. See notes in Herbicide section (page 70-71) for Rely, Gramoxone.
++++
Use 10,000 ppm (10 oz/1 gal) as a low- pressure, large-droplet handgun application.
12
0
See Sucker Control (page 78) for specific recommendation details.
Delay preharvest fruit drop and delay fruit maturity.
ReTain
++++
Not more than one 333 g pouch
(50 g a.i.)
per acre
12
7
Single Pick Harvest. Applying one pouch of ReTain per acre 3 to 4 weeks prior to the anticipated beginning of the normal harvest period of untreated fruit will delay the harvest period by 7 to 10 days. Timing of ReTain application is critical. Apply ReTain closer to harvest in hot years. Use a 100% organosilicone adjuvant at a final concentration of 0.05 to 0.1% (v/v) in the spray tank for optimal response. Reduce the amount of a.i. per acre to 25 g on sensitive varieties such as Gala. Consult the label. Multiple Pick Harvest. Applying one pouch of ReTain per acre 1 to 2 weeks prior to the anticipated beginning of the normal harvest period of untreated fruit will improve quality and storage potential of later picked apples (2nd and 3rd pick fruit). Applications at this time will not typically delay the start of the harvest, but will help control the maturation rate of the later harvests.
22 Goals
Options
Relative1
Effectiveness (+)
or
Importance (*)
Amount per2
Re-entry
Interval
(hours)
Preharv.
Interval
(days)
Comments
100 gal
Acre
Delay or reduce preharvest fruit drop or both.
Preload NAA
(Fruitone-L or PoMaxa)
+++
2 oz
48
2
Make multiple applications of 5 ppm each week for the 4-week period prior to the normal start of the harvest period for each variety.
NAA
(Fruitone L or PoMaxa)
+++
8 to 32 fl. oz
48
2
Temporarily suppress any fruit drop by applying 10 to 20 ppm (depending on variety) of NAA. A second application can be applied 7 to 10 days later. See Growth-Regulating Chemicals section (page 73) for details.
ReTain plus NAA
(Fruitone L or PoMaxa)
+++++
One 333 g pouch of ReTain plus 8 to 16 fl. oz Fruitone L or PoMaxa per 100 gal per acre
12
7
Apply the ReTain plus Fruitone L or ReTain plus ProMaxa combination (plus adjuvant) as a tank-mix 2 weeks prior to the start of the normal harvest. This combination can provide improved fruit drop control and firmness retention compared to ReTain or NAA alone.
Reduce fruit russeting in susceptible varieties.
ProVide 10SG
Novagib 10L
(continue applications started at petal fall)
++++
++++
2.1 - 3.5 fl. oz
(60 to 100 g)
20 oz per acre/appl.
4
4
0
See Growth-Regulating Chemicals section (page 73) for recommendation details.
Reduce fruit cracking of susceptible varieties (e.g., Stayman).
Pro-Vide 10SG
+++
3.5 - 7.0 fl. oz
(100 - 200 g)
4
0
Make the first application at least 2 to 3 weeks before fruit cracking is likely to be observed in the orchard. Repeat at 14 to 21 day intervals until harvest. See Growth-Regulating Chemicals section (page 73) for details. Do not apply to trees that received ProVide applications for russet suppression.
Novagib 10L
+++
2 to 4 pt per acre/appl.
4
Promote lateral branching of current season’s growth.
Promalin
+++
0.8 oz/gal of
water (125 ppm)
12
None
See Growth-Regulating Chemicals section (page 73) for recommendation details.
1Effectiveness ratings range from + = poor control to +++++ = excellent control. Importance ratings range from * = minor importance to ***** = very important.
2Rates expressed as amount per 100 gal for dilute and amount per acre are for concentrate applications based on a tree-row-volume of 400 gal/acre.
23 SECOND COVER AND LATER SPRAYS (continued)
Goals
Options
Relative1
Effectiveness (+)
or
Importance (*)
Amount per2
Re-entry
Interval
(hours)
Preharv.
Interval
(days)
Comments
100 gal
Acre
Disease Management
Control summer diseases (white rot, black rot, sooty blotch, flyspeck, black pox).
Scout orchard.
Prune out fire blight strikes.
*****
*****
Apply cover sprays at 10- to 14-day intervals. Use a 7- to 10-day interval during wet, rainy periods. If thiophanate-methyl or a phosphite fungicide is not used in cover sprays, it is important to combine captan with sufficient ziram to increase fungicide rate to 8 to 10 lb/acre in order to control sooty blotch and flyspeck. Be sure to observe 77-day preharvest interval when using metiram or mancozeb. Use captan where there is a history of white rot.
Fungicides
Captan 50W
Captan 4L
Captan 80WDG
++++
++++
++++
1 qt
8 lb
4 qt
5 lb
24
24
24
0
0
0
Ziram 76DF
++++
6 lb
48
14
Sovran 50WG
++++
4 to 6.4 oz
12
30
A maximum of four applications and 25.6 oz of Sovran 50WG can be used per acre per season. It is weak on black pox.
Flint 50WG
+++++
1.5 to 2.5 oz
12
14
A maximum of four applications and 11 oz of Flint 50WG can be used per acre per season. For optimal control of white rot, tank mix with captan. Flint is weak on black pox.
Pristine 38W
+++++
14.5 to 18 oz
12
0
A maximum of four applications and 72 oz of Pristine can be used per acre per season. It is weak on black pox.
Thiophanate Methyl 85WDG
Topsin 4.5FL
Topsin M WSB
+++++
+++++
+++++
0.6 to 0.8 lb
15 to 20 fl oz
¾ to 1 lb
48
48
48
1
1
1
captan
50W or
4L or
80 WDG
+
mancozeb 75DF
+++++
3 lb
24
77
24
Goals
Options
Relative1
Effectiveness (+)
or
Importance (*)
Amount per2
Re-entry
Interval
(hours)
Preharv.
Interval
(days)
Comments
100 gal
Acre
Control summer diseases (continued).
Captan 80WDG
+
ProPhyt3
++++
3.75 to 5 lb
4 pt
24
4
0
0
Inspire Super 2.82EW
Rotated with:
Captan 80WDG
+
ProPhyt3
+++++
12 fl oz
3.75 to 5 lb
4 pt
12
24
12
14
0
0
This combination has provided good summer disease control. It is not especially effective on black pox, so if you use this program and have a history of black pox, begin the cover sprays with an EBDC+captan combination, or captan+thiophanate methyl, then switch to this program at 3rd cover. Do not make more than 5 applications (60 oz) of Inspire Super per year.
Aprovia
+++++
5.5 to 7 fl oz
12
30
Luna Sensation
++++
4 to 5.8 fl oz
12
14
Apply Luna Sensation in tank mixture with captan for optimal control of white rot.
Merivon
+++++
4 to 5.5 fl oz
12
0
Control Colletotrichum pathogens: Glomerella leaf spot/rot/Bitter rot.
Refer to fungicides used for Petal Fall and 1st cover applications.
Suppress necrotic leaf blotch on Golden Delicious.
ziram 76DF
zinc oxide 39.8%
+++++
+++++
6 lb
1 pt
48
0
14
0
Sprays from mid-June through early August are most important.
Control powdery mildew.
Scout orchard.
*****
Need for additional fungicides is based on the number of infections on newly unfolded leaves and continued growth pressure. See recommendations for petal fall if powdery mildew is present.
1Effectiveness ratings range from + = poor control to +++++ = excellent control. Importance ratings range from * = minor importance to ***** = very important.
2Rates expressed as amount per 100 gal for dilute and amount per acre are for concentrate applications based on a tree-row-volume of 400 gal/acre.
3Other phosphite fungicides are also labeled on apples. See the discussion of phosphite fungicides in the Fungicides and Bactericides section (p. 55).
25 SECOND COVER AND LATER SPRAYS (continued)
Goals
Options
Relative1
Effectiveness (+)
or
Importance (*)
Amount per2
Re-entry
Interval
(hours)
Preharv.
Interval
(days)
Comments
100 gal
Acre
Control Alternaria blotch.
Pristine 38W
+++++
14.5 to 18.5 oz
12
0
Make first application of Pristine around third or fourth cover (mid-June). Apply two additional applications at 10- to 14-day intervals. These applications will also control other summer diseases on Delicious. Rotations of Pristine and captan plus a phosphite fungicide are also effective and will help limit QoI fungicide use since only 4 applications are allowed by the label. Use in conjunction with a preventive mite management program. Do not make more than 4 applications or apply more than 72 oz of Pristine per season.
Control blister spot.
Fungicides
Aliette WDG
Phostrol
++++
++++
0.5 to 1 gal
2.5 to 5 pt
12
4
14
0
Fruit are most susceptible to blister spot 2 to 8 weeks following petal fall.
Insect Management
*****
See IPM practices for codling moth (page 34) and oriental fruit moth (page 36) to determine the need for and timing of insecticide sprays. Keep trap bottoms clean, and replace lures at recommended intervals.
The need for insecticides against codling moth should be based on pheromone trap captures and the degree-day model.
In orchards where mating disruption for codling moth and OFM is not being used, late season (late July and August) sprays of CheckMate OFM-F or application of Isomate OFM-TT is recommended for late season control of OFM. OFM populations often increase during August and September in apples.
Control codling moth and oriental fruit moth.
Monitor pheromone traps weekly for adult activity.
*****
Insecticides
(See First Cover.)
*****
OFM Mating Disruption
Isomate OFM-TT
CheckMate OFM-F
+++++
+++++
50-100 disp.
1 to 2 oz
26 Goals
Options
Relative1
Effectiveness (+)
or
Importance (*)
Amount per2
Re-entry
Interval
(hours)
Preharv.
Interval
(days)
Comments
100 gal
Acre
Control tufted apple bud moth.
Monitor pheromone traps weekly for adult activity.
Thin fruit to avoid excessive clustering.
*****
****
See IPM Practices for tufted apple bud moth (page 36) to determine the proper timing of insecticide applications.
Clustering of fruit is conducive to higher levels of tufted apple bud moth injury.
Insecticides
Intrepid
Delegate 25WG
Altacor 35WDG
Exirel 0.83SE
Belt 4SC
+++++
+++++
+++++
+++++
+++++
—
—
—
—
—
6 to 10 oz
4.5 to 7 oz
2.5 to 4.5 oz
8.5 to 17 oz
3 to 5 fl oz
4
4
4
12
12
14
7
5
3
14
Insecticide sprays for TABM are recommended only in orchards with a history of damage. See section on IPM practices for TABM (page 36) to properly time sprays. This spray often overlaps with the need for sprays of late-emerging codling moth.
Bacillus thuringiensis
Dipel 2X
CryMax
XenTari
+++
1 to 2 lb
1 to 2 lb
1 to 2 lb
4
4
4
0
0
0
For best results apply Bacillus thuringiensis (Bt) products at no less than 2X concentration. If using Bts, it is important to monitor codling moth with pheromone traps because Bts do not control CM.
Control apple maggot.
Erect red sticky spheres in early June to monitor adults.
****
Erect sticky traps baited with fruit essence lures on outside rows nearest abandoned orchards or other sources of flies. Check weekly. Threshold level is a cumulative of 5 flies per trap. If the threshold is exceeded again 2 weeks after spraying, apply again. Adults can emerge from June through September. Historically, peak emergence generally occurs from mid-July to early August.
Insecticides
Imidan 70WP
Admire 4.6SC
Assail 30SG
Surround WP
++++
++++
+++
+++
¾ lb
—
—
—
3 lb
2.8 oz
8 oz
20 to 50 lb
24
12
12
4
7
7
7
—
Apply Surround at 7- to 14-day intervals, or after a heavy rain, because thorough, uniform, and consistent coverage is important. Rate of Surround will vary with tree size.
1Effectiveness ratings range from + = poor control to +++++ = excellent control. Importance ratings range from * = minor importance to ***** = very important.
2Rates expressed as amount per 100 gal for dilute and amount per acre are for concentrate applications based on a tree-row-volume of 400 gal/acre.
27 SECOND COVER AND LATER SPRAYS (continued)
Goals
Options
Relative1
Effectiveness (+)
or
Importance (*)
Amount per2
Re-entry
Interval
(hours)
Preharv.
Interval
(days)
Comments
100 gal
Acre
Control white apple leafhopper or potato leafhopper.
Insecticides
Actara 25WDG
Admire 4.6SC
Assail 30SG
Sivanto 200SL
+++++
+++++
+++++
+++++
—
—
—
—
2 to 2¾ oz
2.8 oz
2.5 to 4 oz
7 to 10 oz
12
12
12
4
14
7
7
14
Threshold level for second brood white apple leafhopper nymphs (which occur in late July to early August) is one nymph per leaf. Treatment will eliminate the need to treat for adults immediately before harvest. Generally, low rates of insecticides will control leafhoppers.
Control brown stink bugs, including brown marmorated stink bug.
Insecticides
Actara 25 WDG
Belay SC
Danitol 2.4EC
Warrior 2.08CS
Endigo ZC
Leverage 2.7SE
+++
+++
+++
+++
+++
+++
4.5 to 5.5 oz
6 to 12 fl oz
16 to 21 fl oz
1.3 to 2.8 fl oz
5 to 6 fl oz
3.6 to 4.4 fl oz
12
12
24
24
24
12
35
7
14
21
35
7
Brown marmorated stink bug is established throughout apple production areas in NC, SC, and TN. It is in the early stages of infesting northeast GA. Expect infestations to be most common from August through mid-September.
*Check with local extension service for Section 18 labels that may be approved for BMSB.
Control spotted tentiform leafminer.
Insecticides
Delegate WG
Intrepid 2F
+++++
+++++
—
—
4.5 to 7 oz
8 to 12 fl oz
4
12
7
14
Leafminer infestations have become a rare occurrence in the past decade. A threshold level of two mines per leaf for second generation larvae (June to July), or 4 mines per leaf for third generation (August), should be used to dictate the need for STLM control.
Control green apple and spirea aphids.
Insecticides
Admire 4.6SC
Actara 25WDG
Assail 30SG
Belay
Sivanto 200SL
+++++
+++++
+++++
+++++
+++++
—
—
—
—
—
2.8 oz
4.5 oz
2.5 to 4.0 oz
4 to 6 fl oz
7 to 10 oz
12
12
12
12
4
7
35
7
7
14
Threshold level for green apple aphid is 50% infested terminals. Control is most important on young trees and in dwarf plantings. On mature trees, a higher threshold is tolerable. Biological control can often preclude the need for chemical control.
Control Comstock mealybug.
Insecticides
Diazinon 50WP
Actara 25WDG
Assail 30SG
Movento 2SC
+++++
+++
+++++
+++
1 lb
—
—
—
4 lb
4.5 oz
4 to 8 oz
6 to 9 fl oz
96
12
12
24
21
35
7
7
Applications should be made near the second or third cover spray. Comstock mealybug is an unpredictable pest, and orchards with a history of problems are most susceptible.
28 Goals
Options
Relative1
Effectiveness (+)
or
Importance (*)
Amount per2
Re-entry
interval
(hours)
Preharv.
interval
(days)
Comments
100 gal
Acre
Control woolly apple aphid.
Insecticides
Diazinon 50WP
Movento 2SC
+++++
+++
1 lb
—
4 lb
6 to 9 fl oz
24
12
21
7
Woolly apple aphid control can be difficult if insecticides are applied after populations reach large densities. Use a threshold of 10% infested shoots. Movento should be applied preventively in early July for best control. Also, an adjuvant must be used with Movento.
Control redbanded leafroller.
Insecticides
See insecticides for tufted apple bud moth.
Redbanded leafroller is a sporadic problem. If damage is done, it is usually by the last generation, which lays eggs from mid August to mid September.
Control lesser apple worm.
Insecticides
See insecticides for codling moth.
Lesser apple worm is a sporadic pest of importance in isolated areas. If damage occurs, it is usually by the third generation, which occurs in August.
Control dogwood borer.
Insecticides
Lorsban 50W
Lorsban 4E
++++
+++++
3 lb
1.5 qt
—
—
96
96
28
28
Apply insecticides with a handgun sprayer to the trunk, especially to burr knots and graft unions. Moths can lay eggs from mid-May through September, so treatment before July is optimal. Lorsban should be applied with a handgun sprayer from no more than 4 ft or with a shielded sprayer to prevent drift onto foliage or fruit.
1Effectiveness ratings range from + = poor control to +++++ = excellent control. Importance ratings range from * = minor importance to ***** = very important.
2Rates expressed as amount per 100 gal for dilute and amount per acre are for concentrate applications based on a tree-row-volume of 400 gal/acre.
29 SECOND COVER AND LATER SPRAYS (continued)
Goals
Options
Relative1
Effectiveness (+)
or
Importance (*)
Amount per2
Re-entry
Interval
(hours)
Preharv.
Interval
(days)
Comments
100 gal
Acre
Control European red mite and twospotted spider mite.
Monitor trees for mite activity.
*****
See IPM practices for European red mite (page 35). European red mite and twospotted spider mite threshold levels before July are 7 mites per leaf (85% infested leaves) and 10 mites per leaf (90% infested leaves) during July and August. If populations are near threshold level, check for predatory mites in 3 to 4 days to determine if biological control reduces mite populations. In orchards with Alternaria blotch, a threshold of 1 mite per leaf (50% infested leaves) should be used to minimize stress to trees.
Miticides
Acramite 50WS
Nexter 75WP
Portal 0.4EC
Apollo SC
Savey 50DF
Zeal 72WDG
Envidor 2SC
Kanemite 15SC
Nealta 1.67SC
wettable sulfur
summer oil
+++++
++++
++++
++++
++++
+++++
+++++
+++++
+++++
+
++
—
—
—
—
—
—
—
— —
1½ to 3½ lb
½ to 1 gal
¾ to 1 lb
4.4 oz
1 to 2 pt
4 oz
3 oz
2 to 3 oz
16 to 18 oz
21 to 21 fl oz
13.7 oz
5 to 15 lb
½ to 1% soln.
12
12
12
12
12
12
12
12
12
12
12
7
25
14
45
28
28
14
14
7
7
0
If Apollo or Savey was used at petal fall, do not reapply at this time. Do not expect complete control with a single application of oil or sulfur. These materials must be applied multiple times for best results. Applying a highly refined summer oil when mite populations are beginning to increase (first and second covers) will help suppress European red mite infestations. Do not apply captan 2 weeks before or after an oil spray.
Weed Management
Spot-treat with herbicide to control difficult-to-manage perennial weeds.
glyphosate
*****
++++
See Weed Response to Herbicide table
(pages 56 to 58).
4
1
Apple trees are especially sensitive to glyphosate applied in late summer and fall. Avoid contacting tree bark and especially foliage.
Bermuda grass control.
Poast
*****
++++
1.5 pt followed by
1 pt
12
14
Apply when Bermuda grass has 4 to 6 inches of new growth in spring. Follow with a second application when Bermuda grass has 4 inches of regrowth.
30 POSTHARVEST
Goals
Options
Relative1
Effectiveness (+)
or
Importance (*)
Amount per2
Re-entry
Interval
(hours)
Preharv.
Interval
(days)
Comments
100 gal
Acre
Plant Growth Regulators
Control fruit storage scald.
DPA
++++
2½ pt per one gal of water as a dip or spray to harvested fruit.
See Growth-Regulating Chemicals section (page 73) for complete details.
To maintain apple flesh firmness, fruit acidity and minimize scald.
SmartFresh
++++
See Growth-Regulating Chemicals section (page 73) for complete details.
Weed Management
In areas where heavy populations of winter annual weeds are present, apply herbicide as part of vole management program. Application of a fall preemergence herbicide will delay the spring herbicide application to early May or later.
Apply POST or PRE+POST herbicide.
See herbicide guide.
***
See herbicide guide.
See product labels.
1Effectiveness ratings range from + = poor control to +++++ = excellent control. Importance ratings range from * = minor importance to ***** = very important.
2Rates expressed as amount per 100 gal for dilute and amount per acre are for concentrate applications based on a tree-row-volume of 400 gal/acre.
31 32
Tree Row Volume (TRV):
A Model for Determining Spray Volume
The TRV model is a simple and objective method of determining (1) the volume of tree canopy on an acre of orchard, regardless of row spacing, tree size, age, or other factors; and (2) the dilute application water rate and chemical quantity for dilute (1X) applications or concentrate chemical load per acre needed to effectively spray each particular orchard, regardless of pruning and tree canopy density.
The TRV concept rests on these assumptions: Each row of trees is a wall of foliage, and water and chemical loads required can be related to the volume and density of foliage within that wall. Only three measurements must be made: (1) The distance between rows of trees; (2) the maximum tree height to be sprayed; and (3) the spread from drip line to drip line, which must be accurately measured to at least the nearest foot. In addition, an assessment of tree density is needed to calculate the TRV of an orchard.
Using these measurements, the TRV of any orchard can be calculated using the following formula:
Step 1:
Step 2: feet of row per acre (from Step 1)
x tree height (ft)
x cross-limb spread (ft)
= cu ft of foliage per acre.
Steps 1 and 2 determine the volume of foliage canopy per acre in the orchard.
Step 3: Select the number from Table 1 (below) that best indicates the canopy density of each separate orchard or block.
The cubic feet of foliage volume from Step 2 and the tree density established in Step 3 are used to calculate the water volume required per acre for a dilute spray application to provide maximum chemical load with a dilute airblast sprayer (applied to runoff).
Step 4:
cu ft of foliage
per acre
(from Step 2)
gallons of dilute solution to be applied per acre for a maximum application
canopy density
(from Step 3)
x
=
1,000 cu ft
Example:
Consider an orchard that has rows spaced 25 feet apart, trees 20 feet high, a spread of 17 feet from drip line to drip line, and a tree density of 0.85.
Step 1:
Step 2: 1,742.4 ft x 20 ft x 17 ft = 592,416 cu ft
Step 3: Density has been given as 0.85 gal/1,000 cu ft
Step 4:
However, general pesticide applications are not applied to runoff. Using 70 percent (0.70) of the “to runoff” calculated rate reduces the dilute application just to the point of drip, or what we call “pesticide dilute.” Table 2 (opposite) gives the adjustments to the “TRV calculated water rates for dilute to runoff” water application rate for various chemicals used and types of spray applications. The 503.5 gallons per acre in the example above is used to illustrate the adjustments in Table 2.
Table 1. Canopy density adjustments in tree row volume (TRV) model.
0.70 gal/1,000 cu ft
Trees extremely open, light visible through entire tree, less than 15 scaffold limbs per tree or young tree.
0.75 gal/1,000 cu ft
Trees very open, 18 to 21 scaffolds per tree, light penetration throughout tree, healthy spurs in tree canopy.
0.80 gal/1,000 cu ft
Trees well pruned, adequate light in trees for healthy spurs throughout trunk and scaffold limbs, many holes or openings in foliage where light is visible through tree.
0.85 gal/1,000 cu ft
Trees moderately well pruned, reasonable spur population within canopy, tree thick enough that light is not visible through bottom ⅔ of tree.
0.90 gal/1,000 cu ft
Trees pruned minimally, spurs inside canopy are weak due to limited light, very few openings where light is visible throughout the tree.
0.95 gal/1,000 cu ft
Little or no pruning, spurs dead or very weak in canopy, very little light visible throughout the tree.
1.00 gal/1,000 cu ft
Tree unpruned, extremely thick, no light visible anywhere through tree canopy, trees more than 20 ft high.
43,560 sq ft per acre
=
feet of row
per acre
distance between rows (ft)
43,560 ft2
=
1,742.4 ft
25 ft
592,416 cu ft
x 0.85 gal
=
503.5 gal per acre will apply a dilute application to runoff
1,000 cu ft 33
Table 2. Adjustments in tree row volume (TRV) calculated water rates per acre for various chemicals and spray applications.
Type of spray and chemical application
% of the calculated TRV dilute to runoff gallonage to be used for a dilute application
Actual gallons/acre to be used in previous TRV example orchard
1Pre-petal fall dilute pesticide application (adjusted because of incomplete foliage development)
56
282
Dilute pesticide application (from petal fall on and all other applications not specifically mentioned)
70
352
ProVide and Promalin (as a fine mist)
40 to 50
201 to 252
Spur Red Delicious thinners and dormant oil applications
100
504
Thinners for other varieties
70 to 90
352 to 453
Vegetative growth inhibitor
80 to 90
403 to 453
Preharvest Ethrel plus stop-drop spray
100 to 120
504 to 605
1To use this reduced gallonage requires accurate nozzling to top of trees and good air displacement within trees (i.e., reduced tractor speed).
Table 3 (below) demonstrates how the chemical load and water volume for concentrate sprays can be easily calculated from the TRV model.
The TRV model is accurate for dilute and concentrate chemical applications with conventional airblast sprayers, using water volumes as low as 150 gallons per acre. Below this gallonage, the physics of droplet size and impingement on the foliage can become a limiting factor in obtaining effective deposition on trees. Thus, if the TRV model calculates a water application rate of less than 150 gallons per acre, a 150 to 200 gallon rate should be considered a minimum in a conventional airblast sprayer, or be sure you are using a concentrate engineered sprayer (higher air speed) that will ensure adequate impingement of the spray solution on the tree surfaces at low water volume.
Table 3. How to calculate concentrate application rates.
Concentrate pesticide application
(3X water rate)1
Dilute pesticide TRV gallonage
=
352 gal/acre
=
117 gal/acre
Concentrate rate
3X
Concentrate pesticide chemical load per acre (2X to 4X)2
Rate of pesticide
per 100 gal
x
Dilute pesticide TRV
gal per acre
=
2.0 x 352
=
7.1 lbs/acre
100 gal
100
5X or greater3
Rate of pesticide
per 100 gal
x
Dilute pesticide TRV
gal per acre
x 0.8
=
2.0 x 352 x 0.8
=
5.6 lbs/acre
100 gal
100
1Assume the example orchard was to be sprayed at 3X concentration. 2Rate per 100 gal dilute. Example based on 2.0 lb pesticide/100 gal. 3This adjustment for concentrate application (5X or greater) should be made if spraying conditions are good and trees are properly matched to the sprayer. Adequate spray coverage cannot be assumed with concentrate application if sprays are applied during windy conditions or to thick, oversized trees.
Dwarf High-Density Orchards
Dwarf high-density orchards represent a special situation for TRV applications. Most high density orchard TRV water application rates calculate out at well below the minimum desirable gallonage for good droplet impingement (below 150 gallons/acre). We have consistently found improved efficacy of pesticide application and improved time efficiency by calibrating for double the TRV. This raises the water application rate above the minimum desirable gallonage, then you must drive every other row middle to reduce actual water volume per acre of orchard back to true TRV calculated rate. Pesticides are applied on a normal interval, alternating drive middles.
The reality of sprayer calibration and nozzling for chemical applications is that until the proper chemical load is appropriately delivered and deposited on leaf and fruit surfaces, the spray you apply cannot be considered an effective pesticide application. 34
IPM Practices for Selected Pests
Plum Curculio
Adults overwinter in leaf litter in and around orchards. In the spring when the daily maximum temperature exceeds 70°F, adults emerge, mate, and lay eggs under fruit skin. Adults generally begin to enter orchards shortly before bloom, with most adults present by the end of petal fall. Depending on weather conditions, new adults can continue to enter until at least the first cover spray. Damage is observed as feeding or oviposition scars and is cosmetic. Larval development can occur in apples that drop off the tree. Adult plum curculio are ¼-inch-long weevils with a curved snout; they are mottled black, gray, and brown with two bumps on each wing cover and a white marking across the back. Eggs hatch within a few days after being laid and feed in the fruit. The mature larva is ¼-inch long, white, slightly curved, and legless. The first generation adults usually emerge about 8 to 10 weeks later: late June or July depending on location. These adults will also feed on and damage fruit. Although plum curculio is capable of completing two generations per year in many southeastern locations, in most years only one is completed.
Scouting and Control: Plum curculio is very difficult to monitor, because traps are inconsistent and adults are difficult to observe and readily drop from trees when disturbed. After bloom, check twice weekly for plum curculio adults, feeding damage, and egg-laying scars. Typically, an insecticide at petal fall is sufficient for control, but occasionally emergence may be protracted under high population densities or cool conditions and a second application is necessary at first cover. A model developed in NY that predicts damage to apple by first generation adults is based on accumulating degree-days (50°F base, use codling moth degree-day table below) beginning at petal fall (90% of petals fallen) of ‘Delicious’ apples. The model predicts that insecticidal control is no longer necessary after 310 degree-days have accumulated from petal fall. First generation adults emerge and can feed on apples from late June through July, depending on location.
Apple Maggot
The apple maggot usually completes one generation per season, although a partial second generation can occur in certain years, particularly at elevations below 1,200 feet. Adult fly emergence from overwintering pupae in the soil is unpredictable and can occur from June through August, but the peak emergence is usually between mid July and early August. About 7 days after emergence, flies become sexually mature and mate, after which females deposit eggs under the skin of apples by puncturing them with their ovipositor. After a few days a small maggot hatches from the egg and the maggot tunnels within the fruit. When mature, the maggot exits the apple, drops to the ground, and burrows into the soil, where it completes development and forms a pupa. The pupa is the overwintering stage, and it emerges as a fly the following summer. If fly emergence is early in the season, some of their progeny emerge the same season rather than overwinter. In addition, a small percentage of flies may not emerge until 2 to 4 years later.
Weather conditions are important in dictating the timing and length of fly emergence. Pupae that are overwintering in lighter soils and in sunny areas emerge before those in heavier soils and shady areas. Sufficient soil moisture is also necessary for flies to emerge from soil-borne pupae. Drought delays or prevents many flies from emerging. Also, abandoned orchards (or even a few non-sprayed trees) and wild hawthorn trees adjacent to apples are potential sources of flies, and are a threat to commercial orchards located within a distance of about 400 yards.
Monitoring and Control: Monitor flies with red sticky spheres that are baited with a fruit essence lure. Baited spheres catch two to four times as many adults as non-baited spheres. In orchards with no history of maggot injury, a minimum of three red spheres should be placed on the outside row of an orchard closest to the suspected source of flies (e.g., abandoned orchard). Hang spheres in trees with fruit, and remove fruit within 18” of the sphere so that the sphere is highly visible to flies. In orchards with a history of damage, traps can also be placed in the interior of orchards on the southern side of trees. When using baited spheres, apply an insecticide after catching 5 flies cumulatively. Repeat an application at 14-day intervals if captures again reach 5 flies. Although the timing of emergence can vary among years, in most years the critical timing for insecticidal control is late July to early August.
Codling Moth
Codling moths begin to emerge and mate during April or early May, depending on location, and complete two generations per season. Depending on location and the year, a partial or complete third generation may occur, most commonly at elevations below about 1,000 feet. Eggs generally begin to hatch near the first cover spray, and soon larvae tunnel into and feed inside fruit. The mature larvae are similar to oriental fruit moth larvae, being ½-inch long and pinkish-white with legs. Unlike the OFM, codling moth larvae do not have an anal comb.
In recent years the codling moth has become a serious problem in orchards throughout the Southeast. Factors associated with problem orchards are (1) bin piles stored near orchards and/or (2) insecticide-resistant populations. Bins are an ideal environment for overwintering larvae, and when they complete their development the following spring the adults disperse to nearby orchards. Orchards within 100 to 150 yards of bin piles are particularly prone to infestation. Insecticide resistance has been detected in a number of orchards where problems have persisted for one or two years.
Codling Moth Degree-Day Model
The codling moth degree-day model is used to predict adult emergence and egg hatch of each of the two to three 35
generations that occur each year. The model has been in existence for more than 30 years and was recently modified to more accurately reflect southeastern populations. However, the model may not be accurate where moths emerging from nearby bins are a primary source of codling moth, because these individuals usually emerge later than those in natural habitats in the orchard.
Base a decision to spray insecticides against codling moth on pheromone trapping and the codling moth degree-day model. Use pheromone traps to determine the starting point of the model (biofix) and to gauge the intensity of populations. The degree-day model predicts percent of adult emergence and egg hatch for each of the two to three generations of codling moth that annually occur in the Southeast. The model is quite accurate for the first generation, but is less accurate for each successive generation.
To use the model, begin to accumulate degree days when male flight begins in the spring, which is referred to as biofix. The biofix date is determined with pheromone traps to detect the first sustained catch of two or more moths in the spring. Traps should be placed in orchards near the tight cluster stage of bud development, and checked one to two times per week. Hang traps at a density of one trap per 10 acres of orchard. Traps hung in the upper third of the canopy catch more moths than those in the lower canopy and are a preferred location. Once biofix is determined, degree days are calculated daily. It is only necessary to check traps once per week after biofix is determined. Use the table on page 39 to determine the number of degree days occurring at various maximum and minimum daily temperatures.
First Generation CM: Recommendations are provided for low- and moderate-to-high population densities. Low-density orchards are those where less than 0.2 percent of fruit were damaged the previous year and pheromone trap catches do not exceed 1 to 2 moths per trap per week anytime during the first generation (up to about 1000 DD after biofix). Under these conditions, a single application at 350 DD after biofix is sufficient.
In moderate-to high-density orchards, apply two insecticide applications at 14 to 21 days apart, the first at 100 to 250 DD after biofix: 100 to 150 if using a product which depends primarily on ovicidal activity for control (i.e., Intrepid or Rimon), and 250 if using other insecticides that target early stage larvae. Additional applications may be necessary if trap captures remain high (greater than 7 moths per trap).
A second emergence of overwintering adults sometimes occurs between 500 and 800 degree days after biofix. This is often referred to as the “B peak” and may be associated with insecticide-resistant individuals in the population. Hence, pheromone trapping is important throughout the flight period.Relationship between degree-day accumulations from biofix and percentages of codling moth adult emergence and egg hatch.
Cumulative
Degree Days
% Adult Emergence
% Egg
Hatch
0 (Biofix)
5
0
1
10
0
50
13
0
100
17
0
150
22
0
200
29
0
250
36
0
300
43
0
350
52
3
400
60
8
450
67
12
500
74
22
550
80
30
600
84
36
650
88
42
700
91
54
750
93
62
800
95
64
850
96
67
900
97
73
950
98
81
1000
99
92
1050
10
100
1100
12
1
1150
15
1
1200
19
2
1250
23
3
1300
28
4
1350
33
5
1400
39
8
1450
45
11
1500
51
15
1550
57
20
1600
63
24
1650
69
29
1700
74
35
1750
78
38
1800
82
48
1850
86
64
1900
88
65
1950
91
68
2000
93
71
2050
94
73
2100
95
75
2150
96
78
2200
97
81
2250
98
84
2300
98
84
2350
99
85
2400
99
90
2500
10
95
2550
15
98
2600
20
99
2650
25
100
36
Second generation CM: Recommendations are provided for extremely low, low, and moderate-to-high population densities. Extremely low-density orchards may not require an insecticide application (no first-generation damage is observed and pheromone trap catches remain below one moth per trap per week between 1,000 and 2,500 DD after biofix). Low-density orchards require one insecticide application, and recent research indicates the optimum timing is 1,400 to 1,500 DD. These orchards may have no sign of damage by first generation larvae and trap catches between 3 to 5 moths per trap per week between 1,000 to 1,500 DD after biofix. Moderate-to high-density orchards will have fruit damage and higher pheromone trap catches requiring at least two insecticide applications at 14-day intervals, starting about 1,400 DD after biofix, and additional applications if trap captures remain above 5 to 7 moths per trap per week.
Third Generation CM: The model should not be relied upon alone for timing insecticide applications for the third generation, because the model becomes less accurate over time.
Exceptions to the Model: Where codling moth populations are extremely high and where pheromone trap catches remain high between generations, additional insecticide applications at shorter intervals may be necessary. This often occurs in orchards adjacent to abandoned orchards, orchards near bins, or in problem orchards with high populations.
Oriental Fruit Moth
Oriental fruit moths begin to emerge and mate before apple bloom, and eggs begin to hatch at petal fall. Variable spring temperatures cause erratic emergence and egg-laying by first-generation moths. The larvae feed on shoot tips and inside apple fruit. The mature larva is ½-inch long, pinkish-white, and has an anal comb and legs. The only way to distinguish between oriental fruit moth and codling moth larvae is to use a hand lens to examine mature larvae for the presence of an anal comb. Codling moth larvae do not have an anal comb.
Oriental Fruit Moth Degree-Day Model
Base a decision to spray insecticides against oriental fruit moth on pheromone trap catches and a DD model. The model biofix is determined in the same manner as for the codling moth. Use pheromone traps to determine the starting point of the model and to gauge the intensity of populations. The degree-day model predicts adult emergence and egg hatch for the first three of the four or five generations that occur in the Southeast. However, generations overlap later in the season, which makes the degree-day model less useful at this time. The table on page 39 uses daily maximum and minimum temperatures to determine daily DDs for oriental fruit moth (base 45°F). Place traps in the orchards near the green-tip stage of bud development, and check one to two times per week. Hang traps at eye level at a density of 1 trap per 10 acres of orchard. Check traps weekly after the biofix date.
First-Generation OFM: Control of the first generation is often important to prevent first-generation damage and to reduce populations of subsequent generations. First-generation egg laying is usually low on apple, and only one insecticide application between 400 and 500 DD after biofix is necessary, which usually coincides with petal fall.
Second-Generation OFM: If first-generation control was successful, second-generation populations are usually very low. Extremely low-density orchards may not require an insecticide application (pheromone trap catches never exceed 3 moths per trap per week between 800 to 1,600 DD). In low-density orchards (3 to 5 moths per trap per week between 800 and 1,500 DD), make a single insecticide application at 1,400 DD. Moderate- to high-density orchards will have fruit damage, higher trap catches, or both, and may need two insecticide applications 14 days apart starting at 1,100 DD.
Third and Fourth Generations: Use of the degree-day model becomes less useful beginning in July and August due to overlapping of generations. For this reason, rely on pheromone trap captures to determine the need for control measures. Use of a threshold level of 7 moths per trap per week has worked well to minimize damage. In situations where consistently high trap captures occur, mating disruption should be considered (see below).
Tufted Apple Bud Moth
The tufted apple bud moth (TABM) is the most common leafroller occurring on apple in the Southeast. In the 1990s it was the most destructive insect pest of southeastern apples due to insecticide resistance, but populations have greatly reduced since the introduction of new insecticides in the early 2000s. TABM completes two generations per year, with egg laying occurring during June (first generation) and August and September (second generation). Larvae feed on leaves and fruit, with fruit damage usually observed as surface feeding. However, second-generation larvae may also be found feeding within the calyx end of fruit. Unless an individual orchard has a history of damage by this insect, it is doubtful that special precautions need to be taken. Timing is critical to the successful management of this pest. In most instances, one well-timed insecticide application per generation will provide high levels of control. Cultural controls are also important. Maintain a clean orchard floor, particularly in the early spring before bloom, to minimize TABM populations by removing the food source for overwintering larvae. New apple sucker growth and broadleaf weeds are important food sources in the spring. Thinning apples to breakup clusters of fruit also reduces damage.
Tufted Apple Bud Moth Degree-Day Model
A TABM degree-day model similar to that of the oriental fruit moth and codling moth was developed specifically for populations in the Southeast. For calculating degree days from maximum and minimum daily temperatures, use the oriental fruit moth table on page 39 (45°F). Place TABM pheromone traps at the tight cluster to pink stage of bud development at a density of 1 trap per 20 acres of orchard. Biofix is the first date on which a sustained catch occurs and may vary from 2 to 5 moths per trap per week. The cumulative number of degree days from the point of biofix is used 37
to predict percent egg hatch and to time insecticide applications against the first generation.
First-Generation Recommendation: When population densities are sufficiently high or if a short residual insecticide is used (i.e., Bacillus thuringiensis), two insecticide applications per generation may be necessary; make the first application at about 10 percent egg hatch, which occurs at about 800 DD after biofix, and the second application 14 days later. Where populations are low or if using a long residual insecticide (Intrepid, Delegate, Altacor), one application per generation should be made anytime between 10 and 30 percent egg hatch of the first generation, or from 800 to 1,200 DD after biofix.
Second-Generation Recommendation: Population densities of second generation TABM have been low since the registration of highly effective new insecticides such as Altacor, Intrepid, Delegate, and Rimon. In fact, insecticidal control of the second generation has not been necessary in many orchards when one of these products was used against the first generation. Not unless pheromone trap captures exceed about 15 moths per trap by 2,600 DD after biofix (time of 10% egg hatch of the second generation) is an insecticide application recommended. Control is most important on later maturing apples that are harvested after mid September.
Mating Disruption
Mating disruption consists of emitting relatively large amounts of an insect’s sex pheromone into an orchard environment to disrupt the normal mate-location process. Mating disruption prevents or reduces mating and the subsequent laying of fertile eggs, which effectively reduces populations below economically damaging levels. It is effective only in blocks of 5 acres or more. In apples, mating disruption is registered for codling moth and oriental fruit moth. Oriental fruit moth is much easier to control with mating disruption compared with codling moth; use both mating disruption and insecticides against moderate to high codling moth populations. Mating disruption will not control infestations resulting from immigrating fertilized female moths; hence, mating disruption alone is not recommended in blocks located adjacent to a likely source of immigrating moths (such as abandoned orchards or bin storage areas).
Pheromone Dispensers: A number of companies market pheromone dispensers for mating disruption, including hand-applied dispensers that emit pheromones for a relatively long period and sprayable products that last for shorter periods and need to be reapplied. Companies are now marketing pheromone dispensers that contain both codling moth and oriental fruit moth so that a single dispenser type can be used for mating disruption of both insects. Dispensers vary in the amount of pheromone they contain and the length of time during which pheromone is emitted, so read the label beforehand to ensure that dispensers are used properly. Because both codling moth and oriental fruit moth are potential pests in the Southeast, it is highly recommended that dual pheromone dispensers be used in apples.
Timing of Applications: For the codling moth, place pheromone dispensers in the orchard before adults begin to fly in the spring. First emergence of adults usually begins during late bloom or petal fall of Delicious cultivars. Hence, dispenser application should be completed by petal fall. Best results are obtained when dispensers are hung in the upper third of the canopy, because this is where mating occurs.
The oriental fruit moth begins to emerge near green tip of Delicious cultivars, so for season-long control, dispensers should be in the orchard by this time. However, insecticides applied at petal fall for other insects usually control this first generation, so if using oriental fruit moth dispensers only, application can be delayed until just before emergence of the second- or third-generation adults (950 and 1850 DD after biofix, respectively). If using sprayable pheromones for mating disruption, which is only recommended for OFM, make the initial application when hand-applied dispensers are applied. If mating disruption is not used against this insect and pheromone trap captures remain low during the season, a single late-season application in mid to late August will help to suppress late-season populations.
Monitoring Insects: Monitoring codling moth and oriental fruit moth populations is of critical importance to measure the effectiveness of mating disruption and to determine the need for insecticides. Pheromone traps should be used to monitor moth populations, and fruit should also be examined at periodic intervals. When properly used, pheromone trapping can be useful to determine the need for insecticides under mating disruption orchards. Traps should be hung in the upper one-third of the canopy, because that is where codling moth activity is most intense. Traps should be hung at a density of no less than one trap per five acres, and preferably one per three acres, and checked at weekly intervals. Trap captures should be added each week, and when the cumulative number exceeds an average of three moths per trap, an insecticide may be necessary. Threshold levels are based on using large delta-style traps and Trece CM L2 lures, which should be replaced at 12-week intervals.
The type of pheromone lure used in traps is also important. Some lures contain a pear ester kairomone that enhances capture of codling moth and may capture female moths, and is sold as CMDA. Lures to enhance OFM captures contain a combination of OFM pheromone plus codling moth. Finally acetic acid lures placed in traps with the pheromone lures enhance capture of both moths.
European Red Mite Management
Several beneficial arthropods can help keep European red mite (ERM) populations below damaging levels. The most common in the Southeast are the phytoseiid mite (Amblyseius fallacis) and a complex of generalist predators (such as lady beetles and lacewings). However, recent research in North Carolina suggests that neither of these predators overwinters to any significant degree within orchards, so they must be reestablished in orchards in the spring. Hence, practices that delay the buildup of ERM and enable predators to increase before mites become a problem will favor biological control. The two most effective practices 38
are applying a delayed dormant oil spray and avoiding insecticides toxic to these predators.
Monitoring Mite Populations: Use a regular monitoring program to follow the buildup of mite populations and to determine if and when supplemental applications of a miticide are necessary to avoid economic damage. Monitor each contiguous block of apples weekly beginning when adult mites
first appear (which may vary from mid-May to late June). Within each block, examine 5 leaves from each of 10 trees with a visor lens or hand lens. Rather than counting the total number of mites on each leaf, record the number of leaves infested with one or more mites, and estimate mite density from the table below.
Determining the Need for Miticides: When mite populations reach a density of 5 to 10 mites per leaf (80 to 90 percent infested leaves), decide whether to rely on biological control or apply a miticide to prevent mites from increasing to damaging levels. To gauge the potential for biological control with predator mite A. fallacis, count the number of predator mites on sample leaves with a visor lens. If the ratio of A. fallacis to ERM is between 1 to 5 and 1 to 15, biological control is possible. If predators are not present and mite populations are between 5 to 10 mites per leaf, apply a miticide.
Where Alternaria blotch is a problem on Delicious apples, biological control is usually not an option. Alternaria blotch in the presence of mite injury can lead to premature defoliation, so mite populations must be maintained at very low levels. If preventive control measures are not used, miticides should be used when mites reach 1-2 mites per leaf.
Relationship between European red mite density per leaf and % infested leaves.
% Mite-Infested Leaves
(>1 mite/leaf)
Expected No.
Mites per Leaf
40
45
50
55
60
65
70
75
80
85
90
95
0.7
0.9
1.1
1.3
1.6
2.0
2.6
3.4
4.7
6.8
11.4
26.4 39
Codling moth degree days (50°F lower base, 88°F upper base) at various daily maximum and minimum temperatures.
Max
54
56
58
60
62
64
66
68
70
72
74
76
78
80
82
84
86
88
90
92
94
96
Min
20
0
1
1
2
2
3
3
4
5
5
6
7
8
9
9
10
11
12
13
14
15
15
22
0
1
1
2
2
3
3
4
6
6
6
7
8
9
10
10
11
12
13
14
15
15
24
0
1
1
2
2
3
4
4
6
6
7
7
8
9
10
11
11
12
13
14
15
16
26
0
1
1
2
2
3
4
4
6
6
7
7
8
9
10
11
12
12
13
14
15
16
28
0
1
1
2
2
3
4
4
6
6
7
8
8
9
10
11
12
13
14
15
15
16
30
0
1
1
2
2
3
4
5
6
6
7
8
9
10
10
11
12
13
14
15
16
16
32
0
1
1
2
3
3
4
5
6
6
7
8
9
10
11
11
12
13
14
15
16
17
34
0
1
1
2
3
3
4
5
6
7
7
8
9
10
11
12
13
14
14
15
16
17
36
0
1
1
2
3
4
4
5
6
7
8
8
9
10
11
12
13
14
15
16
17
17
38
0
1
1
2
3
4
4
5
6
7
8
9
10
11
11
12
13
14
15
16
17
18
40
0
1
2
2
3
4
5
6
6
7
8
9
10
11
12
13
14
15
16
17
17
18
42
0
1
2
2
3
4
5
6
7
7
8
9
10
11
12
13
14
15
16
17
18
19
44
0
1
2
3
3
4
5
6
7
8
9
10
11
12
13
14
15
15
16
17
18
19
46
0
1
2
3
4
5
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
48
1
2
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
20
50
1
2
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
52
2
3
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
54
-
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
56
-
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
58
-
-
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
60
-
-
-
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
62
-
-
-
-
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
64
-
-
-
-
-
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
66
-
-
-
-
-
-
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
68
-
-
-
-
-
-
-
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
70
-
-
-
-
-
-
-
-
18
19
20
21
22
23
24
25
26
27
28
29
30
31
72
-
-
-
-
-
-
-
-
-
20
21
22
23
24
25
26
27
28
29
30
31
32
74
-
-
-
-
-
-
-
-
-
-
22
23
24
25
26
27
28
29
30
31
32
33
76
-
-
-
-
-
-
-
-
-
-
-
24
25
26
27
28
29
30
31
32
33
34
Oriental fruit moth degree days (45°F lower base, 91°F upper base) at various daily maximum and minimum temperatures.
Max
50
52
54
56
58
60
62
64
66
68
70
72
74
76
78
80
82
84
86
88
90
92
94
96
Min
20
1
1
2
2
3
4
4
5
6
7
8
9
9
10
12
12
13
14
15
16
17
17
18
19
22
1
1
2
2
3
4
4
6
7
7
8
9
10
11
12
12
13
14
15
16
17
18
18
19
24
1
2
2
2
4
4
5
6
7
7
8
10
10
11
12
12
14
15
15
16
18
18
19
20
26
1
2
2
3
4
5
5
6
7
7
8
10
10
11
12
13
14
15
16
16
18
18
19
20
28
1
2
3
3
4
5
5
6
7
8
9
10
10
11
13
13
14
15
16
17
18
19
20
20
30
1
2
3
3
4
5
5
6
7
8
9
10
10
12
13
13
15
16
16
17
19
19
20
21
32
1
2
3
3
4
5
6
6
8
8
9
10
11
12
13
14
15
16
17
18
19
19
20
21
34
1
2
3
3
4
6
6
7
8
8
10
11
11
12
14
14
15
17
17
18
19
20
21
21
36
1
2
3
3
5
6
6
7
8
9
10
11
11
13
14
14
16
17
18
19
19
20
21
22
38
1
2
3
4
5
6
6
7
9
9
10
11
12
13
14
15
16
17
18
19
20
21
21
22
40
1
2
3
4
5
6
6
8
9
9
10
11
12
13
15
15
16
18
18
19
20
21
22
23
42
1
3
4
4
6
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
44
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
46
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
48
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
50
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
52
-
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
54
-
-
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
56
-
-
-
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
58
-
-
-
-
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
60
-
-
-
-
-
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
62
-
-
-
-
-
-
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
64
-
-
-
-
-
-
-
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
66
-
-
-
-
-
-
-
-
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
35
68
-
-
-
-
-
-
-
-
-
23
24
25
26
27
28
29
30
31
32
33
34
35
36
36
70
-
-
-
-
-
-
-
-
-
-
25
26
27
28
29
30
31
32
33
34
35
36
37
37
72
-
-
-
-
-
-
-
-
-
-
-
27
28
29
30
31
32
33
34
35
36
37
38
38
74
-
-
-
-
-
-
-
-
-
-
-
-
29
30
31
32
33
34
35
36
37
38
39
39
76
-
-
-
-
-
-
-
-
-
-
-
-
-
31
32
33
34
35
36
37
38
39
40
40
39 40
Pesticide Resistance Management
General Considerations
Pesticide resistance is a shift in the genetics of a pest population that allows individuals within a previously susceptible population to survive. Resistant pest populations have inherited traits that reduce their susceptibility to individual pesticides or groups of pesticides. Resistance develops in all agricultural pest groups—insects, mites, fungi, bacteria, nematodes, and weeds. Pesticide-resistant individuals are initially quite rare in pest populations. However, when a new pesticide is first used, a very low number of individual pests never previously exposed to the novel chemistry can be expected to be resistant. The frequency of resistant genes to novel chemistries varies tremendously, but history makes it clear that resistant individuals should be expected in all pest groups. By the nature of the process, resistance most often develops to pesticides that are initially very effective and frequently used.
Pesticide resistance management is an effort to slow or prevent the development of resistance. It relies on pest management and pesticide-use strategies to prolong the effective life of pesticides. Resistance management is difficult, especially in high-value crops such as fruit, where high quality standards and limited numbers of registered pesticides make the task more challenging.
Managing resistance requires an understanding of the factors that influence its development. Selection is the process of pesticide-induced selection for resistance. With regular pesticide use, those rare individuals that are naturally resistant survive and reproduce more successfully than their susceptible peers. Resistance frequency refers to the proportion of a pest population that is resistant. Cross resistance refers to a type of resistance in which a pest population develops resistance to more than one pesticide within a chemical family (such as organophosphate insecticides or EBDC fungicides). Multiple resistance involves multiple, independent resistance mechanisms, which often lead to resistance to chemicals from different families (organophosphate and carbamate insecticides, dodine and DMI fungicides). Resistance stability is a key factor in managing resistance. Stability is an estimate of how well resistance persists in a pest population once the pesticide is no longer used. The rate of reversion to a susceptible state varies enormously. But when pesticide use ceases, selective pressure for resistance is removed, and over time resistance will often be reduced. Resistance stability estimates may allow limited use of resistance-prone compounds.
It is important to emphasize that control failures do not confirm resistance. Other factors (poor timing, sprayer calibration or coverage, wash-off, high pH in spray tank water, inappropriate materials, etc.) should be eliminated as causes for control failures before resistance is seriously considered. Factors influencing the development of resistance can be grouped into biological and management categories. Biological factors include pest reproductive rate, mobility of the pest species into and out of untreated areas, and genetic factors such as number of resistance mechanisms, resistance frequency and intensity, and resistance stability. Management factors that influence resistance development include how materials are applied, how often they are used, how long they persist in the field, treatment thresholds, and strategies for using available pesticides. Resistance management efforts study specific pest-pesticide interactions and focus on practical strategies that growers can implement.
Pest management is practical and works in concert with pesticide-use strategies to lessen resistance selection by facilitating prudent, as-needed pesticide use. Pesticide-use strategies work best when implemented as a new pesticide comes into commerce. Pesticide manufacturers, IPM scientists, and growers have come to recognize that using resistance management from the beginning works best. Collecting baseline susceptibilities, defining probable resistance problems beforehand, and proposing pesticide-use strategies to forestall resistance development are the province of manufacturers and IPM scientists. Biologically and economically sound resistance management plans offered pre-sale give growers the best hope for managing resistance. Pesticide-use strategies are often grouped as follows: (1) management by moderation, (2) rotation and mixtures, and (3) saturation.
Moderation means limiting the use of a pesticide. Moderation is employed in concert with IPM practices, such as using treatment thresholds, spraying only specific pest generations or growth stages, maintaining unsprayed wild host reservoirs to act as refuges for genetically susceptible individuals, using pesticides with shorter residual or lower toxicity to important beneficial populations, etc. Moderation should be used to the fullest extent that will provide commercially acceptable control.
Rotation, and in some cases mixtures, are the bulwarks of pesticide-use strategies because an individual pest is less likely to be resistant to two or more differing classes of toxins. In theory, most individual pests resistant to one pesticide will be killed when exposed to a different class of toxin. Rotations depend on having effective, labeled materials with different modes of action. Material cost is a key practical consideration that favors rotation. Mixtures of fungicides have been used successfully to combat disease resistance, although cost lessens the attractiveness of this approach. Mixtures of insecticides and miticides have typically performed poorly. Rotation is seen as the desired approach for insecticides, miticides, and some fungicides.
Saturation, the use of higher pesticide rates to control resistant individuals, is the least attractive resistance management approach, although it has been used to manage resistance to DMI fungicides. Saturation is generally a last resort when there are no other effective, labeled alternatives. In this scenario, higher rates will often provide control for a time, although at greater cost. Synergists, chemicals that increase the toxicity of pesticides, have sometimes been effective in boosting the efficacy of resistance-prone pesticides. As with simple rate increases, saturation with synergists typically provides only short-term benefits.
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Insecticide Resistance Management Strategies
In the southeastern United States, pesticide resistance has been documented in the tufted apple bud moth, codling moth, rosy apple aphid, and European red mite. Currently, codling moth resistance is most important, but good resistance management strategies are required to prevent other pests from developing resistance.
Codling Moth
Insecticide-resistant codling moth populations became prevalent throughout the Southeast in the early 2000s. Resistance to one or more registered insecticides, including Intrepid and Rimon, were detected in a number of orchards in Georgia and North Carolina. In situations where codling moth resistance occurs, populations usually increase to large numbers, and frequent insecticide applications at short intervals (7 to 10 days) are necessary at critical times (between 400 and 800 DD after biofix) to prevent damage. However, such intense insecticide use may lead to higher levels of resistance, so alternative management strategies should be used in conjunction with insecticides. Using mating disruption is strongly encouraged as a resistance management tactic, because this will help reduce population densities more quickly than insecticides alone and, subsequently, the need for insecticide applications. After two to three years of continuous mating disruption, codling moth population densities can be reduced so that only one or two total insecticide applications are needed for season-long control. In addition, make an attempt to avoid using more than two insecticide applications against a single codling moth generation by incorporating codling moth virus (Cyd-X or Carpovirusine) applications into the spray program after two applications have been made. When choosing insecticides, rotate insecticides with different modes of action against each generation. For example, make two applications of the same insecticide against the first generation, but use an insecticide with a different mode of action against the second generation.
Rosy Apple Aphid
The rosy apple aphid has developed widespread resistance to Lorsban, and control failures with Asana, Ambush, Danitol and Diazinon have become more common in recent years. Consequently, neonicotinoid insecticides are now most commonly used for control. It is important to remember that all neonicotinoids (Actara, Assail, Calypso, Belay, and Provado) have a similar mode of action and should be considered the same material for rotation purposes.
The two best times to control rosy apple aphid on apple are (1) tight cluster to pink or (2) petal fall. Do not apply any insecticide with the same mode of action more than once during this time frame, and if possible do not use the insecticide used for rosy apple aphid control more than once during the period when the aphids may occur in apple orchards (through the third or fourth cover spray).
European Red Mite
Avoiding unnecessary miticide applications is the most effective strategy for minimizing the potential for resistance development. A delayed dormant oil application is highly recommended to suppress overwintering populations of European red mite and to improve the potential for biological control to maintain mite populations below damaging levels. On Delicious cultivars, which are susceptible to Alternaria blotch and where preventive control or low threshold levels are recommended for control of European red mite, there is a high potential for developing resistant populations. To reduce this potential, in addition to a delayed dormant oil application, do not use the same miticide in successive years.
Resistance Management Strategies for Plant Pathogens
Resistance of plant pathogens to pesticides has become widespread over the past 40 years as site-specific (systemic) chemicals have been developed and used on many crops and against many pathogens. The broad-spectrum protectants (such as captan and mancozeb) that were used previously had multiple sites of activity in the target pathogens, greatly reducing the likelihood of resistance development.
Resistance has become a problem in the U.S. in at least five pathogens that affect apples during the growing season: Venturia inaequalis, cause of apple scab; Podosphaera leucotricha, cause of powdery mildew; Alternaria mali, cause of Alternaria leaf blotch; Erwinia amylovora, cause of fire blight; and Pseudomonas syringae pv. papulans, cause of blister spot. Resistance of V. inaequalis to dodine (Syllit, initially sold as Cyprex) was first reported in New York in 1969. It has subsequently been reported in several states in the Northeast and Midwest but has not been found in orchards in the Southeast. Resistance of V. inaequalis to the benzimidazole fungicides (benomyl and thiophanate-methyl) was reported shortly after their introduction in 1971 and became widespread in the eastern U.S., including the Southeast, in the mid-1970s. As a consequence they are no longer recommended for apple scab control in the Southeast. The demethylation inhibiting (DMI) fungicides were first introduced in the late 1980s, and reduced sensitivity of V. inaequalis has been reported or suspected in a number of orchards in the Northeast and Midwest. Some growers in NC have also had problems controlling scab with DMI fungicides, suggesting that resistance may be a problem here as well. Resistance of V. inaequalis to strobilurin (QoI) fungicides (Flint and Sovran) has been reported in Virginia. Resistance of Alternaria mali to the QoI fungicides (Flint and Sovran) has been reported in North Carolina. Resistance of Podosphaera leucotricha to EBI and QoI fungicides is evident in Virginia. Resistance of the fire blight bacterium, E. amylovora, to streptomycin (FireWall, Agri-mycin 17, Streptrol) is present in several states but has not been reported in the Southeast. Resistance of P. syringae pv. papulans has been confirmed in an orchard in Tennessee and in New York. There is potential for resistance to the Group 9 fungicides (anilinopyrimidine, AP, cyprodinil, and pyrimethanil), which include Vangard and Scala and are components of Inspire Super and Luna Tranquility, and to the newer Group 7 42
fungicides (carboximide, SDHI, boscalid, fluopyram, fluxapyroxad, and penthiopyrad), which are included in Pristine, Luna Sensation, Luna Tranquility, Merivon, and Fontelis.
To avoid resistance development, minimize the use of fungicides and bactericides in which resistance is likely to develop. Additionally, combine site-specific fungicides with protectant fungicides that have broad spectrum activity. Limit
dodine applications to two to three per year. In areas where dodine resistance first became a problem, it was often used 10 to 12 times throughout the growing season. Similarly, limit streptomycin use for fire blight control to two to four times a year. Make applications only during times favorable for infection. These periods are characterized by open blossoms, dew or rainfall greater than 0.01 inch, an average daily temperature of 60°F or greater, and the accumulation of at least 198 degree-hours greater than 65°F since the first blossoms opened. Use the DMI and QoI fungicides only in combination with broad spectrum protectants, such as captan or EBDC fungicides. Avoid post-symptom applications of site-specific fungicides, such as dodine and the DMI fungicides, because this sets up an ideal situation for selection of resistant strains. Good orchard sanitation practices to maintain pathogen populations at low levels are also an important component of a resistance management program.
Herbicide Resistant Weeds
The reality of herbicide resistant weeds infesting orchards is more likely today than ever. Populations of pigweed and goosegrass resistant to dinitroanaline herbicides (Prowl and Oryzalin) exist in the Southeast. Populations of johnsongrass resistant to carboxylase herbicides (Fusilade DX) also have been documented. Most recently glyphosate resistant weeds have been found across the Southeast and Midwest. Glyphosate resistant weed populations have been verified in Delaware, North Carolina, South Carolina, Georgia, and Tennessee. The two most notable species developing resistance to glyphosate are horseweed and Palmer amaranth. Glyphosate resistant ragweed is suspected and being investigated as well. Growers should be aware that these weeds are in apple production regions and in the event of control failures herbicide programs will have to be altered. If you suspect a problem or need additional information you should contact your county agent with the Cooperative Extension Service.
In order to prevent the development of herbicide resistant weeds growers should take into consideration the following practices:
1. Rotate herbicides with different modes of action (see table below). For example, do not use simazine (Princep, Simazine) continuously. Consider other pre-emergence broadleaf herbicide options. Avoid making more than two applications of the same herbicide in the same year.
2. Scout orchards to identify weeds. Respond quickly to changes in weed populations by controlling weeds
before they spread throughout the entire orchard.
3. Use non-selective post-emergence herbicides in a weed management program.
4. Use herbicides only as needed.
Herbicide Mode of Action Table
MOA Group
Herbicide Members
1
Clethodim (Select, etc.), Fluazifop (Fusilade), Sethoxydim (Poast)
2
Rimsulfuron (Matrix, Pruvin, Solida) and Halosulfuron (Sandea)
3
Oryzalin (Surflan) and
Pendimethalin (Prowl)
4
2,4-D amine, clopyralid (Stinger), fluroxypyr (Starane or Comet)
5
Simazine and Terbacil (Sinbar)
7
Diuron (Karmex, Direx)
9
Glyphosate (Roundup, etc.)
10
Glufosinate (Reckon)
12
Norflurazon (Solicam)
14
Flumioxazin (Chateau), Carfentrazone (Aim, Zeus Prime), Salflufenacil (Treevix), Sulfrentrazone (Zeus Prime)
20
Dichlobenil (Casoron)
22
Paraquat
(Gramoxone, Firestorm, Parazone)
29
Indaziflam (Alion) 43
Effect of pH on Pesticide Activity
Although the pH of spray water does not directly affect resistance development, it can affect the activity of some pesticides. The label on dimethoate, phosmet, malathion, azinphos-methyl, formetanate, ethephon, NAA, and possibly others warns of this effect. When these materials, except NAA, are exposed to a pH above 7.5, they undergo hydrolysis and break down to products that are either less effective or not effective. Excessively acidic conditions may limit uptake of NAA and, therefore, its effectiveness. The actual rate of breakdown depends on solubility and temperature and the total quantity broken down during a given period. For example, captan is hydrolyzed very quickly at alkaline pHs, but because it is very insoluble, the impact of pH is negligible unless captan is allowed to stand for a week or more. Hydrolysis increases with increased temperature. If the time in the spray tank is limited by applying pesticides immediately, then the quantitative amount broken down is limited.
Additives to the spray tank can also be a factor. Calcium chloride, especially when concentrated in the tank and applied in a low volume spray, can increase the pH. The greater the concentration, the greater the alkalinity. The manufacturing process for calcium chloride leaves residues of free lime (calcium hydroxide). The greater the purity of the calcium chloride, the lower the content of calcium hydroxide and the lower the effect on pH.
The water source can be a factor. Although most wells, streams, and rivers in the southeastern growing region are mildly acidic (6.7 plus or minus 0.2) there are exceptions; therefore, check pH a few times before regular use. Ponds are more likely to be alkaline, especially those high in algae and other organisms. These ponds undergo diurnal pH changes as result of dissolved carbon dioxide. Levels greater than 10 have been observed. Alkalinity contributed by CO2 is weakly buffered and readily changed by acidifying agents.
Although not pH-related, some pesticides can be affected by other contaminants in the water. For example, fenbuconazole, not labeled on apples, is greatly reduced in effectiveness by suspended particulates. Still other compounds like 2,4-D and azoxystrobilurin can be very difficult to wash out of the tank and can have a deleterious effect on apples at very low concentrations.
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Orchard Floor Management
The best strategy for managing the orchard floor is to use a noncompetitive grass alley with a vegetation-free strip in the tree row. The vegetation-free strip can be established and maintained with herbicides as described in this section. The permanent grass sod between the tree rows will minimize soil erosion, increase soil aeration and permeability, and support equipment movement through the orchard during wet weather. The vegetation-free strip eliminates competition for water and nutrients, minimizes tree damage or loss from voles during the dormant season, and provides some radiant heat from the soil surface should a spring frost or freeze occur. Herbicides are directed at the soil and weeds underneath the tree.
The vegetation-free strip method is superior to all other orchard floor management options. Vegetation under the tree competes for nutrients and water, resulting in reduced growth, yield, and size of fruit. Another option is the use of organic mulches in the tree row. Examples of mulching materials include straw, wood chips, and grass residue from mowing. These mulches will suppress weed emergence, but weed removal by some means will still be necessary. Mulches can improve the water-holding capacity of some soils. However, there are several concerns regarding the use of organic mulches. The most significant problem is that mulches create an ideal habitat for voles. Also, additional nitrogen may be needed to support the microorganisms that drive decomposition of organic mulches. In poorly drained or waterlogged soils, organic mulches increase the likelihood of phytophthora root rot. Mulches can be expensive and difficult to obtain. Synthetic mulches made from polyethylene, polypropylene, or polyester can be placed in the tree row around the base of the trunk or as a narrow strip down the row. Some newer synthetics allow water and air to pass through the mulch.
Herbicide Considerations
To ensure proper herbicide use, always read the manufacturer’s label before application. All statements on the manufacturer’s label take precedence over any recommendations in this publication.
It is important that herbicide application equipment be properly calibrated to ensure that herbicides are applied at the correct rate. For questions about calibrating your sprayer, contact your county’s Cooperative Extension agent.
Remember that herbicides are applied as a directed spray along each side of the tree row. Flat fan nozzles are most widely used for applying herbicides. They provide excellent spray coverage of weeds and come in several sizes with capabilities to apply a range of spray volumes. Some manufacturers make flat fan nozzles that minimize spray drift, allowing low-pressure spraying. Investing in such spray nozzles decreases the likelihood of off-target herbicide movement.
It is advisable to apply white latex paint to the bottom 2 to 3 feet of the tree trunk of newly planted trees before applying herbicides. Painting the tree trunks reduces the potential for winter as well as herbicide injury, especially from postemergence herbicides. Dip a car wash mitt (wear rubber gloves underneath the mitt) in paint and rub up and down the tree trunk until it is completely painted.
Several herbicides are registered for use in apple orchards. Some are preemergence herbicides that control weeds that have not emerged, and others are postemergence herbicides that control emerged weeds. Preemergence herbicides